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:
ibed 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 2.4.3-1 (for PMF on adjacent streams) and 2.4.3-2 (for local PMF). (The procedure for evaluating the adequacy of site drainage facilities based on a local PMF is outlined in SRP Section 2.4.2.) Corps of Engineers PMF assessments for specific locations or generalized PMF assessments for a geographical area approved by the Chief of Engineers and contained in published or unpublished reports of that agency may be used in lieu of staff-developed analyses. In the absence of such assessments, both large and small basin PMP estimates by NOAA; published techniques of the World Meteorological Organization; and runoff, impoundment, and river-routing models of the Corps of Engineers are used by the staff to estimate PMF discharge and water level at the site. A comprehensive review of the applicant's analyses will be performed and a simplified analysis using calculational procedures or models with demonstrably conservative coefficients and assumptions is performed. If the applicant's PMF estimates are within acceptable margins (described in subsection II), the staff positions will indicate concurrence with the applicant's PMF estimates and the SER safety evaluation report (SER) input will be written accordingly. If the simplified analysis indicates a 10 potential problem with the applicant's estimates, a detailed analysis using more realistic techniques will be performed. The staff will develop a position based on the detailed analysis; 2.4.3-5 DRAFT Rev. 4 - April 1996 resolve, if possible, differences between the applicant's and staff's estimates of PMF design basis; and prepare the SER input accordingly. Wind-generated wave action will be independently estimated using Corps of Engineers criteria such as the "Shore Protection Manual." When sufficient water depth is available,