Document: NUREG-0800
Document ID: 5d71ab44-4cbd-4694-9e2c-eb9b02b902ef
Document Type: srp
Title: ICE EFFECTS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340546.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.7
CFR Part: 
CFR Title: 

Content:
d requirements in such situations. Ice loading must have been included in the structural design basis, if severe icing is possible. - (4) If floating ice is prevalent, based on regional icing history, consideration of impact forces on the safety-related intakes must be a consideration in the design basis. The dynamic loading 2.4.7-2 Rev. 2 - July 1981 caused by floating ice must be included in the structural design basis. (5) If ice blockage of the river or estuary is possible, it must be demonstrated that the resulting water level in the vicinity of the site has been considered in establishing the flood and water supply design bases. If this water level would adversely affect the intake structure, or other safety-related facilities, it must be demonstrated that an alternate safety-related water supply will not also be adversely affected. B. The applicant's estimates of potential ice flooding or low flows are acceptable if the estimates are no more than 5% less conservative than the staff's estimates. If the applicant's estimates are more than 5% less- conservative than the staff's,* the applicant -should fully document and justify its estimates or accept the staff's estimates and redesign applicable flood protection. The suggested criteria of Regulatory Guide 1.27 apply when the water supply comprises part of the ultimate heat sink. III. REVIEW PROCEDURES Applicable literature describing historical occurrences of icing in the region is reviewed to determine if icing protection should be considered in the design of safety-related facilities. If considered necessary, the most likely types of icing conditions (floating ice, river blockage by ice buildup, frazil, etc.) are listed, and the potential impact on plant design of each type is identified. Criteria of the Corps of Engineers and others provide a means of assessing icing impact and methods of mitigating adverse effects. For each type of icing condi- tion, preliminary independent estimates of the "worst case"