Document: NUREG-0800
Document ID: 3e2b0f8e-404f-49b4-8dde-3452e69e6218
Document Type: srp
Title: PROBABLE MAXIMUM FLOOD (PMF) ON STREAMS AND RIVERS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070241.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.3
CFR Part: 
CFR Title: 

Content:
timating the severity of such an event. This problem can be avoided by using a deterministic approach to DRAFT Rev. 4 - April 1996 2.4.3-4 assess design basis events. Such an approach will account for the practical physical limitations of natural phenomena that contribute to the severity of a given event. This criterion is applicable to SRP Section 2.4.3 in that it specifies the hydrologic phenomenon (i.e., PMF) addressed in this section. In general terms, it also specifies the level of conservatism that must be used in assessing the severity of the PMF for the purpose of determining the design bases for the structures, systems, and components important to safety. Meeting the requirements of GDC 2 provides a level of assurance that those structures, systems, and components important to safety will not experience a flood more severe than that for which they were designed.8 2. Paragraph 100.10(c) of 10 CFR Part 100 requires that the site's physical characteristics (including seismology, meteorology, geology, and hydrology) be taken into account when determining the acceptability of a site 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 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 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 hydrologic phenomena of severity up to and including the PMF.9 III. REVIEW PROCEDURES For conditions 1 and 2 (described in subsection II), the methods used for evaluating flooding potential are separated into two parts--PMF on adjacent streams and local PMF. The review procedure is outlined in the attached Figures