Document: NUREG-0800
Document ID: 904b56ce-40c5-4058-b0ad-837d98f63c2a
Document Type: srp
Title: PROBABLE MAXIMUM FLOOD (PMF) ON STREAMS AND RIVERS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0707/ML070730405.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.3
CFR Part: 
CFR Title: 

Content:
sufficient margin for the limited accuracy, quantity, and time period in which the historical data have been accumulated; 2.4.3-5 Revision 4 - March 2007 B. Appropriate combinations of the effects of normal and accident conditions with the effects of the natural phenomena; and C. The importance of the safety functions to be performed. The first specification was adopted in recognition of the relatively short history available for severe natural phenomena (e.g., floods) on the North American continent and, when based on probabilistic considerations only, the potential for underestimating the severity of such an event. This problem can be avoided by using a deterministic approach to 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 should be used in assessing the severity of the PMF for the purpose of determining the design bases for the SSC important to safety. 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 is evaluated pursuant to other SRP sections. 2. Sections 100.10(c) and 100.20(c) of 10 CFR Part 100 require that the physical characteristics of a site (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 should contain a description of the hydrologic characteristics of the site and region and