Document: NRC Regulatory Guide
Document ID: a5ee4c78-1135-4bb6-8d54-e974a3402f87
Document Type: regulatory_guide
Title: An Approach for Plant-Specific, Risk-Informed Decisionmaking: Graded Quality Assurance
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1221/ML12216A017.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.176
CFR Part: 
CFR Title: 

Content:
fety principles. Guidelines for making that demonstration with due consideration for the scope of the GQA program are summarized below. Other equivalent guidelines are acceptable. GQA programs need to reflect the multiplicity of current regulations and programs to which some SSCs are subject. For example, some SSCs may need to be excluded from certain reduced QA control categories if those SSCs are also governed by more stringent American Society of Mechanical Engineers (ASME) Code provisions to meet the requirements of 10 CFR 50.55a. In such instances, the ASME Code requirements must be met. 1.176-1i 2.2.1 Engineering Evaluation Guidelines The engineering evaluation should assess whether the impact of the proposed change is consistent with the defense-in-depth philosophy. An acceptable set of guidelines for making that assessment is summarized below. Other equivalent decision guidelines are acceptable. * A reasonable balance among prevention of core damage, prevention of containment failure, and consequence mitigation is preserved. * Over-reliance on programmatic activities to compensate for weaknesses in plant design is avoided. " System redundancy, independence, and diversity are preserved commensurate with the expected frequency and consequences of challenges to the system and uncertainties (e.g., no risk outliers). * Defenses against potential common cause failures are preserved and the potential for introduction of new common cause failure mechanisms is assessed. " Independence of barriers is not degraded. * Defenses against human errors are preserved. " The intent of the General Design Criteria in Appendix A to 10 CFR 50 is maintained. The engineering evaluation should also assess whether the impact of the proposed change is consistent with the principle that sufficient safety margins are maintained. An acceptable set of guidelines for making that assessment is summarized below. Other equivalent decision guidelines are acceptable. • Codes and standards or