Document: NUREG-0800
Document ID: 5657a07e-c0b2-48ce-aaad-64d91609c4b3
Document Type: srp
Title: ICE EFFECTS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0701/ML070100648.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.7
CFR Part: 
CFR Title: 

Content:
without loss of capability to perform their safety functions. The criterion further specifies that the design bases for these SSC shall reflect the following: A. Appropriate consideration of the most severe natural phenomena historically reported for the site and its 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 those 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 on the North American continent and, as a result, the potential for underestimating the severity of such events, based on probabilistic considerations only. 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 to contribute to the severity of a given event. 2.4.7-5 Revision 3 - March 2007 This criterion is relevant to this SRP section in that it addresses the potential effects of ice on the hydrological characteristics of the plant site. In general terms, it also specifies the amount of conservatism that should be used to determine the severity of icing phenomena for the purpose of assessing the adequacy of the design bases used or SSC important to safety. This is a similar standard as that applied in reviewing ESPs or COLs. Meeting the requirements of GDC 2 provides assurance that SSC important to safety have been designed to withstand the most severe icing phenomena likely to occur. 2. Sections 100.10(c) and 100.20(c) of 10 CFR Part 100 require that physical characteristics of a site (including seismology, meteorology, geology, and hydrology) be taken into account when determining its acceptability for a nuclear power reactor. To satisfy