Document: NUREG-0800
Document ID: ac43f632-9db1-4857-9f56-bfba45965456
Document Type: srp
Title: * These are modifications to a plant’s design, operations, or other activities that require NRC approval. These modifica
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0232/ML023250195.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19
CFR Part: 
CFR Title: 

Content:
component cooling, room cooling, or any interlocks have been altered by an application. Other dependencies that licensees should consider include the dependency on automatic system initiation and the conditions that must exist for automatic start, essential manual actions to initiate or control the system, and the resources required to fulfill mission success (e.g., water sources, air, fuel oil). When applicable, licensees should factor these dependencies into the analysis of the change. • When proposed changes deal with proceduralized test and maintenance actions or applicable technical specification conditions, the modeling of test and maintenance unavailabilities and the modeling of restoration errors for the affected systems/components should be reviewed. Changes to the frequency of each test or maintenance activity, its approximate duration, the components repositioned for the action, the verification activities after test and maintenance, and the availability of the system during the test procedure should have been factored into the change analysis. • Operational history (i.e., plant-specific operational experience) should be considered in the review of the system models and especially in the review of how the proposed change will affect system operation. Considerations like recurring check valve problems (e.g., back-leakages), water hammer events, or flow blockages by sludge or debris should also be considered in the analysis. SRP 19-A7 • The potential for common cause failures, including those potentially resulting from the change, should have been evaluated and modeled where appropriate. Review guidance for the evaluation of common cause failures is provided in Section A.7 of this SRP chapter. • The function of the modeled system should remain consistent with that required in the event tree models. Success criteria and event sequence conditions should be correctly modeled and consistent with the definition in the event trees. When fault tree