Document: NRC Regulatory Guide
Document ID: 70415715-297f-4d60-841c-514b0372a131
Document Type: regulatory_guide
Title: 02/2017 (Rev. 5)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1608/ML16082A501.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.26
CFR Part: 
CFR Title: 

Content:
dards that may be proposed by applicants or licensees as an alternative means to comply with NRC requirements. Background In the early 1970s, the NRC staff developed a quality classification system to provide licensees with guidance for satisfying GDC 1. The system consists of four quality groups, A through D; methods for assigning components to those quality groups; and specific quality standards applied to each quality group. When the NRC issued Revision 2 and Revision 3 of this guide, 10 CFR 50.55a, “Codes and Standards,” required that only components of the reactor coolant pressure boundary be designed, fabricated, erected, and tested to the highest available national standards; this corresponded to the quality standards for Quality Group A of the NRC system. Revision 4 was issued to align this guide with the final rule (Ref. 8), published on March 15, 1984, amending 10 CFR 50.55a to incorporate by reference the criteria in Section III of the ASME Code, as they relate to the design and fabrication of Class 2 and 3 components (Quality Group B and C components, respectively). Revision 5 of this guide provides better correlation between wording differences that exist between the ASME Code and the rule that were not addressed in Revision 4. Because the quality group classification system is well-established, this revision of RG 1.26 retains the method described in previous versions for determining acceptable quality standards for Quality Group B, C, and D components. Other systems not covered by this guide, such as instrument and service air, diesel engines and their generators and auxiliary support systems, diesel fuel, emergency and normal ventilation, fuel handling, and radioactive waste management systems, should be designed, fabricated, erected, and tested to quality standards commensurate with the safety function to be performed. The evaluation to establish the quality group classification of these other systems should consider the guidance provided for