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
CFR Part: 
CFR Title: 

Content:
terion further specifies that the design bases for these structures, systems, and components shall reflect the following: a. Appropriate consideration of the most severe natural phenomena historically reported for the site and surrounding area, with sufficient margin for the limited accuracy, quantity, and time period in which the historical data have been accumulated; 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 events. This problem can be avoided by using a deterministic approach to assess 2.4.2-5 DRAFT Rev. 4 - April 1996 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 2.4.2 in that it specifies the hydrologic phenomenon (i.e., flooding) addressed in this section. In general terms, it also specifies the level of conservatism that must be used to assess the severity of the flood for the purpose of determining the design bases for the structures, systems, and components important to safety. Meeting the requirements of this criterion provides a level of assurance that structures, systems, and components important to safety have been designed to withstand the most severe flood likely to occur.10 2. Section 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 its acceptability for a nuclear power reactor. To satisfy the hydrologic requirements of 10 CFR Part 100, the applicant's SAR