Document: NUREG-0800
Document ID: 4f5104c1-f91e-4f7d-a8f7-b8b18e630618
Document Type: srp
Title: INTERNAL FLOOD PROTECTION FOR ONSITE EQUIPMENT FAILURES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550043.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.4.1
CFR Part: 
CFR Title: 

Content:
ismically supported system, then only seismically-qualified systems should be assumed to be available to mitigate the effects of the analyzed break (since a seismic event may have caused the failure). 3.4.1-6 Revision 3 - March 2007 The environmental effects of piping failures are assessed in accordance with SRP Section 3.6.1, and the determination of mechanistic rupture locations and the resulting dynamic effects are evaluated in accordance with SRP Section 3.6.2. 4. A review of the applicant's risk assessment of external and internal flooding should be performed In consultation with the organization responsible for the review of the probabilistic risk assessment to identify potentially significant vulnerabilities to flooding, including an analysis of flooding during shutdown conditions. A failure modes and effects analysis may be performed to determine whether the flooding consequences resulting from failures of such liquid-carrying systems close to essential equipment will not preclude required functions of safety systems. 5. A review of the SAR to ascertain if safety-related systems or components are capable of normal function while completely or partially flooded. 6. A review of plant arrangement and layout drawings to determine if safety-related equipment or components are located within individual compartments or cubicles which act as positive barriers against possible means of flooding, and if barriers or other means of physical separation are utilized between redundant safety-related trains. The review also will identify possible flow paths from interconnected nonsafety-related areas to rooms that house safety-related SSCs (e.g., leakage through interconnecting doorways). 7. A review of the design features that will be used to mitigate the effects of internal flooding (e.g. adequate drainage, sump pumps, etc.) if these features are safety-related to ensure adequate time to perform a safe shutdown. Only seismically-qualified systems should be assumed to be