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:
grity, or has repaired a significant amount of tubes as a result of free span degradation, the application should provide a more thorough analysis of the effects of the proposal on the risk associated with ISGTR. Containment Isolation: • Whether the proposed change affects systems that perform or support the isolation function. • Whether the proposed change affects systems that prevent or mitigate core damage sequences initiated during periods of reduced containment functionality (e.g., shutdown). • Whether the proposed change affects the ability to restore containment function during such periods (e.g., AC power, plant procedures). Igniters: • Whether the proposed change affects the igniters or any applicable support systems. ECC Restoration Before Vessel Failure: • If credit was taken in the estimate of LERF for recovery of cooling before vessel failure, whether the proposed change affects performance of any system thus credited (including support systems). • Whether the proposed change affects other accident management strategies credited in the PRA (e.g., external vessel flooding). RCS Pressure at Vessel Failure: • Whether the proposed change affects the capability to depressurize the RCS. SRP 19-A24 Venting: • Whether the proposed change affects the capability to vent the containment. Containment Heat Removal: • Whether the proposed change affects systems credited in containment heat removal (including front-line and support systems). • Whether the proposed change affects the frequency or severity of ATWS sequences. For each of the above considerations that apply, reviewers should ascertain that the licensee adequately evaluated the effects and took them into account in calculating the change in LERF. c. Evaluation Findings The safety evaluation report should contain findings equivalent to the following. • The calculation for the change in LERF resulting from a proposed change has systematically taken into account the dominant causes of