Document: NUREG-0800
Document ID: 496b5bd8-c9a2-4cf6-a703-e41c51e155ec
Document Type: srp
Title: CHANNEL MIGRATION OR DIVERSION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1819/ML18190A201.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.9
CFR Part: 
CFR Title: 

Content:
s: 1. Compliance with GDC 2 requires that nuclear power plant SSCs important to safety be designed to withstand the effects of natural phenomena such as earthquake, tornado, hurricane, flood, tsunami, and seiche without loss of capability to perform their safety functions. The GDC further specifies that the design bases for these SSCs shall reflect the following: A. Appropriate consideration of the most severe of the natural phenomena that have been historically-reported for the site and surrounding area, with sufficient margin for the limited accuracy, quantity, and time period in which the historical data have been accumulated; 2.4.9-8 Draft Revision 4 – September 2018 B. Appropriate combinations of the effects of normal and accident conditions with those of the natural phenomena; and C. The importance of the safety functions to be performed. Channel migration and/or river diversion has the potential for causing flooding or low water elevations at certain sites, thus adversely affecting sources of surface water required for safety-related cooling the proposed plant. Accordingly, GDC 2 requirements are imposed to ensure that components and structures associated with the ultimate heat sink will continue to function, thereby keeping the plant in a safe shutdown condition. For applications pursuant to 10 CFR Part 52, meeting the applicable requirements of 10 CFR 52.17 and 10 CFR 52.79 that correspond to GDC 2 provides a level of assurance that the most severe hydrologic site characteristics have been identified; whether GDC 2 is met with respect to the adequacy of the associated design bases will be evaluated pursuant to other SRP sections. 2. Compliance with GDC 44 requires that a system be provided to transfer heat from SSCs important to safety. The system is to function under normal and accident conditions, assuming a single failure. GDC 44 applies to SRP Section 2.4.9 because the ultimate heat sink for the power plant can consist of complex water supply sources,