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
CFR Part: 
CFR Title: 

Content:
e and mitigative) to core damage, containment failure or bypass, and the balance among defense-in-depth attributes. The licensee should select the engineering analysis techniques, whether quantitative or qualitative, traditional or probabilistic, appropriate to the proposed TS change. The licensee should assess whether the proposed TS or TS change meets the defense-in-depth principle. Defense in depth consists of numerous elements that can be assessment guidelines. Other equivalent acceptance guidelines also may be used. 16.1-6 Revision 1 - March 2007 Consistency with the defense-in-depth philosophy is maintained if: (i) A reasonable balance among prevention of core damage, prevention of containment failure, and consequence mitigation is preserved (i.e., the proposed TS change does not change the balance among these principles of prevention and mitigation to the extent required by 10 CFR 50.36 (Reference 9)). TS change requests should consider whether anticipated operational changes made by a TS change could introduce or could increase the likelihood of new accidents or transients (as required by 10 CFR 50.92) (Reference 14). (ii) Over-reliance on programmatic activities to compensate for weaknesses in plant design is avoided (e.g., use of high reliability estimates based primarily on optimistic program assumptions). (iii) System redundancy, independence, and diversity are maintained commensurate with the expected frequency and consequences of challenges to the system (e.g., there are no risk outliers). The licensee should consider: (1) Whether appropriate restrictions are in place to preclude simultaneous equipment outages that would erode the principles of redundancy and diversity. (2) Whether compensatory actions when entering the modified AOT for pre-planned maintenance are identified. (3) Whether the TS change specifies that voluntary removal of equipment from service should not be scheduled when adverse weather conditions or other situations that likely may