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:
FR 50.92) (Ref. 14). b. Over-reliance on programmatic activities to compensate for weaknesses in plant design is avoided, e.g., use of high reliability estimates that are primarily based on optimistic program assumptions. c. 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 following items should be considered by the licensee. i. Whether there are appropriate restrictions in place to preclude simultaneous equipment outages that would erode the principles of redundancy and diversity, ii. Whether compensatory actions to be taken when entering the modified AOT for pre-planned maintenance are identified, iii. Whether it is specified that voluntary removal of equipment from service should not be scheduled when adverse weather conditions (or other situations when the plant may likely be subjected to abnormal conditions) are predicted, and iv. Whether the impact of the TS change on the safety function should be taken into consideration. For example, what is the impact of a change in the AOT for the low- pressure safety injection system on the overall availability and reliability of the low- pressure injection function? d. Defenses against potential common cause failures are maintained and the potential for introduction of new common cause failure mechanisms is assessed, e.g., TS change requests should consider whether the anticipated operational changes associated with a change in an AOT or STI could introduce any new common cause failure modes not previously considered. e. Independence of physical barriers is not degraded, e.g., TS change requests should address a means of ensuring that the independence of barriers has not been degraded by the TS change (e.g., when changing TS for containment systems). f. Defenses against human errors are maintained, e.g., TS change requests should consider whether the anticipated operation changes