Document: NUREG-0800
Document ID: 7f6b0af0-d79e-4704-9eac-aa03109a7731
Document Type: srp
Title: RISK-INFORMED DECISIONMAKING: TECHNICAL SPECIFICATIONS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0425/ML042520260.pdf
Revision Date: 2023-06
Chapter: 16
Section ID: 16.1
CFR Part: 
CFR Title: 

Content:
tely evaluated prior to and while performing any maintenance activity. A viable program is able to uncover risk-significant plant equipment outage configurations in a timely manner during normal plant operation. This can be accomplished by quantitatively evaluating the impact of, for example, equipment unavailability, operational activities like testing or load dispatching, or weather conditions on plant risk. The need for a third tier stems from the difficulty in identifying all possible risk-significant configurations under Tier 2 that will ever be encountered over extended periods of plant operation. In addition, the review of Tier 3 for TS changes should ensure that the guidance contained in Regulatory Position 2.3.7 of Regulatory Guide 1.177 is met. Risk Evaluation for STIs The reviewer should ensure that the licensee has identified the STIs to be evaluated; determined the risk contribution associated with the subject STIs; determined the risk impact from the change to the proposed STI; and performed sensitivity and uncertainty evaluations to address uncertainties associated with the STI evaluations. Additional detailed guidance on the evaluation of proposed STI changes is contained in the following sections. Risk Evaluation for All TS Changes The scope and the level of PRA necessary to fully support the evaluation of a TS change depend on the type of TS change being sought. However, in some cases, a PRA of sufficient scope may SRP 16.1-15 Rev. 0 - August 1998 not be available. This will have to be compensated for by qualitative arguments, bounding \< analyses, or taking compensatory measures. i. Breadth and Depth of PRA Review The breadth and depth of the PRA review should be addressed in the review for TS changes. The breadth and depth of the review will depend on several factors: a) The emphasis placed on traditional analysis as opposed to PRA in establishing the basis for the TS change. If the justification for the change is based on well founded