Document: NRC Regulatory Guide
Document ID: c7a40fcc-fc9d-4eb2-ad86-f9f5b0f04c82
Document Type: regulatory_guide
Title: Plant-Specific, Risk-Informed Decisionmaking:  Technical Specifications (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1920/ML19206A489.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.177
CFR Part: 
CFR Title: 

Content:
hen adverse weather conditions are predicted, or when the plant may be subjected to other abnormal conditions, and DG-1287, Page 10 d. whether the impact of the TS change on the safety function should be taken into consideration (e.g., the impact of a change in the CT for the low-pressure safety injection system on the overall availability and reliability of the low-pressure injection function). 2.2.2 Technical Specification Change Maintains Sufficient Safety Margin (Principle 3) The licensee’s engineering evaluation should assess whether the impact of the proposed TS CT or SF change is consistent with the principle that sufficient safety margins are maintained (Principle 3 in RG 1.174). An acceptable set of guidelines for making that assessment is summarized below. Other equivalent decision guidelines are acceptable. Sufficient safety margins are maintained under the following circumstances: a. Codes and standards (e.g., American Society of Mechanical Engineers, Institute of Electrical and Electronics Engineers) or alternatives approved for use by the NRC are met (e.g., the proposed TS CT or SF change does not conflict with approved codes and standards relevant to the subject system). b. Safety analysis acceptance criteria in the final safety analysis report are met, or proposed revisions provide sufficient margin to account for analysis and data uncertainties (e.g., the proposed TS CT or SF change does not adversely affect any assumptions or inputs to the safety analysis, or, if such inputs are affected, justification is provided to ensure sufficient safety margin will continue to exist). For TS CT changes, an assessment should be made of the effect on the final safety analysis report acceptance criteria, assuming the plant is in the condition addressed by the proposed CT (i.e., the subject equipment is inoperable) and there are no additional failures. Such an assessment should result in identifying all situations in which entry into the condition addressed by