Document: NUREG-0800
Document ID: 22df8787-ae92-4706-b796-d1b326c09e3c
Document Type: srp
Title: POTENTIAL DAM FAILURES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340533.pdf
Revision Date: 2023-06
Chapter: 2
Section ID: 2.4.4
CFR Part: 
CFR Title: 

Content:
eaffirm the maximum or minimum water levels based on any new information will be described and the results and conclusions stated. Sample statements for CP reviews follow: The staff concludes that the plant design flood elevation, at plant grade of 50 feet MSL, is acceptable and meets the requirements of General Design Criterion 2, 10 CFR Part 100, and 10 CFR Part 100, Appendix A, with respect to potential hazards due to dam failure floods. This conclusion is based on the following evaluation. The distance (more than 300 miles) to upstream reservoirs of appre- ciable size is such that the staff assessment leads to the conclusion that their arbitrarily assumed failure, under postulated combinations of floods and earthquakes of the severity discussed in Regulatory Guide 1.59, would not constitute a threat to the plant. Dam failure-caused "worst case" floods were evaluated by the appli- cant based upon failures with consideration of only the location and sizes of upstream impoundments, and not on inherent capability of such structures to resist earthquakes, volcanic activity and severe landslide-induced floods. The most severe flood of this kind was estimated based upon an assumed catastrophic failure of Dam A some 420 miles upstream. The peak flow at the site from such a flood was estimated to be 3,000,000 cfs. This flow is estimated to occur about *two days after the dam failure and reach elevation 41 feet MSL, 9 feet below plant grade. A volcanically-induced flood was assumed to cause a domino-type failure of the three dams on the tributary B River from a volcanic eruption of Mt. D. The evaluation indicated such an event could cause the second most severe artificial flood that would reach the site. This event was estimated to produce a peak flow at the site of 2,800,000 cfs and a water level of 39 feet MSL, 11 feet below plant grade. 2.4.4-4 Rev. 2 - July 1981 V. IMPLEMENTATION The following is intended to provide guidance to applicants and licensees regarding the