Document: NUREG-0800
Document ID: 32179098-f78d-4852-9c29-1e5e3abb2705
Document Type: srp
Title: RISK-INFORMED DECISION MAKING:  TECHNICAL SPECIFICATIONS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0703/ML070380228.pdf
Revision Date: 2023-06
Chapter: 16
Section ID: 16.1
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CFR Title: 

Content:
e damage frequency (CDF) and large early release frequency (LERF) for the TS change requested. In addition, those sections address cases when the scope of the licensee's PRA does not include a Level 2 (containment performance) analysis, and when, according to the guidelines of RGs 1.174 and 1.177, such an analysis is needed. TS submissions for AOT changes should be evaluated against the risk acceptance guidelines in this section in addition to 2 ICCDP = [(conditional CDF with the subject equipment out of service)-(baseline CDF with nominal expected equipment unavailabilitics)] x (duration of single AOT under consideration). 3 The ICCDP acceptance guideline of 5.0E-7 is based upon the hypothetical situation of subject equipment at a representative plant out of service for five hours, causing the CDF of the plant with an assumed baseline CDF of 1.0E-4 per reactor year to increase conditionally to 1.0E-3 per reactor year during the five-hour period. This basis assumes that the majority of repairs can be made in five hours or less and that the NRC has accepted this level of risk for operating plants. 16.1-8 Revision 1 - March 2007 those in RG 1.174. Application of all risk acceptance guidelines to TS modification proposals will be consistent with the fundamental principle that TS changes result in small increases in the risk to the health and safety of the public (Principle 4, as described in the "Discussion" section of RG 1.177) (Reference 8). General guidance for evaluating the risk impact from TS and other changes is in SRP Section 19.1. TS change evaluations may involve some small increase in risk as quantified by PRA models. The usual argument is that such a small increase is offset by the many beneficial effects of the change not modeled by the PRA. The numerical guidelines ensure that the risk increase is small and provide a quantitative basis for the risk increase according to modeled or quantified aspects of the TS change. The numerical guidelines for an