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:
requiring support from other systems. Eventually, the categorization of all support functions should be consistent, e.g., the safety significance of the functions requiring support in the upper-tiered system corresponds to the relevant function in the support system. 2.1.4 Safety-Significance Categorization of Components The final categorization of system functions and the components that support the high safety-significant system function is selected by an integrated assessment of quantitative and qualitative risk insights as described in Regulatory Position 2.3. The safety-significance categorization assigned to components (and to support system functions that can be treated as component functions for initial categoriza- tion) is based on the safety significance of the function the component supports. Components that support only low safety-significant functions should be classified low safety significant. The safety significance of components supporting high safety-significant func- tions need not always be high, but each such categorization as low safety significant should be explicitly evaluated and documented and in conform- ance with licensee-defined guidelines. Justification for categorizing a component's safety significance as low based on high reliability alone will not be acceptable, because the high reliability may be the result of the QA controls applied. If it is not the quality controls that are the cause of the high reliability, the justification should describe the source of the high reliability. 2.2 Demonstration of Conformance with Safety Principles Once the full set of low safety-significance candidates has been identified, it is necessary to demonstrate that the proposed changes to the QA requirements for these candidates do not violate the safety 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