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:
sion 3 - March 2007 IV. EVALUATION FINDINGS The reviewer verifies that the applicant has provided sufficient information and that the review and calculations (if applicable) support conclusions of the following type to be included in the staff's safety evaluation report. The reviewer also states the bases for those conclusions. The internal flood protection review included all systems and components whose failure could prevent safe shutdown of the plant and maintenance thereof or result in significant uncontrolled release of radioactivity. Based on the review of the applicant's proposed design criteria, design bases, and safety classifications for safety-related SSCs necessary for a safe plant shutdown during and following the flood condition from either external or internal causes, the staff concludes that the design of the facility for flood protection conforms to the requirements as set forth in 10 CFR 50, Appendix A, GDC 2 and GDC 4. This conclusion is based on the applicant having met these requirements with respect to protection of SSCs important to safety from the effects of external and internal flooding by: 1. Identifying all possible sources of internal flooding, including all pipe breaks postulated in SRP Sections 3.6.1 and 3.6.2, full circumferential breaks of non-seismic moderate energy piping, failures of non-seismic internal and external tanks and vessels, backflow through drains, and operation of the fire protection system. The application also considers possible flow paths from non-safety related areas into areas containing safety- related SSCs. 2. Using a method that has been reviewed and found acceptable by the staff to protect SSCs important to safety from flooding by external and internal causes. The design includes the separation of redundant trains of safety-related SSCs, the use of protective barriers and enclosures wherever necessary, the placement of essential SSCs above internal flood levels, and an analysis that shows that any