Document: NUREG-0800
Document ID: 81f4143f-227f-4d30-9822-097124aa5c05
Document Type: srp
Title: FLOODS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070240.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.2
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CFR Title: 

Content:
eteorology, geology, and hydrology) be taken into account when determining its acceptability for a nuclear power reactor. To satisfy the hydrologic requirements of 10 CFR Part 100, the applicant's SAR must contain a description of the surface and subsurface hydrologic characteristics of the site and region and an analysis of the PMF. This description must be sufficient to assess the acceptability of the site and to assess the potential for those characteristics to influence the design of plant structures, systems, and components important to safety. Meeting this requirement provides a level of assurance that plant structures, systems, and components important to safety are designed to withstand appropriately severe hydrologic phenomena. 11 III. REVIEW PROCEDURES Construction permit (CP) stage reviews are carried out under this SRP section to evaluate the significance of the controlling flood level with regard to the plant design basis for flood protection. At the operating license (OL) stage, a brief review is carried out to determine if new information has become available since the CP review and to evaluate the significance of the new information with regard to the plant design basis for flood protection. New information might arise, for instance, from the occurrence of a new maximum flood of record in the site region, from identification of a source of major flooding not previously considered, from construction of new dams, from flood plain encroachments, or from advances in predictive models and analytical techniques. If the CP stage evaluation of flooding potential has been carefully done, all sources of major flooding should have been considered and any new floods of record should fall well within the design basis. Improvements in calculational methods may occur, but generally will be concerned with increased accuracy in stream flow and water level predictions rather than with substantive changes in the flows and levels predicted. Where the OL review reveals