Document: NUREG-0800
Document ID: aee3277d-bcab-4cf4-bdb2-fb607503b041
Document Type: srp
Title: PROBABLE MAXIMUM FLOOD (PMF) ON STREAMS AND RIVERS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340529.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.3
CFR Part: 
CFR Title: 

Content:
e (OL) reviews that have received detailed PMF reviews during the CP review, the CP conclusions will be referenced. Any flood potential not identified during the CP review will be noted. If.Regulatory Guide 1.59, Position 2, is elected by the applicant, a statement describing lesser design bases will be included in the findings with a staff conclusion of adequacy. A sample statement for a CP review follows: The staff concludes that the plant flood design meets the requirements of General Design Criterion 2 and 10 CFR Part 100 and is acceptable. This conclusion is based on the following evaluation: The probable maximum flood (PMF) resulting from the probable maximum precipitation (PMP) on the ABC River drainage basin yielded an estimated maximum stillwater level at the intake structure on the D & E Canal of about 5.0 feet MSL, which is about 5 feet below its design flood level. The PMF resulting from a local PMP storm on the drainage basins for the small streams near the site yielded an estimated maximum still- water level of about 60 feet MSL, which is about 20 feet below plant grade. 2.4.3-4 Rev. 3 - April 1989 The local PMF resulting from the estimated local PMP was found not to cause flooding of safety-related facilities, since the site drainage system will be capable of functioning adequately during such a storm. Catch basins will be provided as part of the storm drainage system and will be located throughout the plant site to drain local areas. The plant yard will be graded with gentle slopes away from high points at the plant buildings, and storm water will drain away from the buildings into the local streams at lower elevations. V. IMPLEMENTATION The following is intended to provide guidance to applicants regarding the NRC staff's plans for using this SRP section. Except in those cases in which the applicant proposes an acceptable alternative method for complying with specified portions of the Commission's regulations, the method described herein will be used