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:
dam failures and the domino failure of a series of dams must be discussed. Approved models of the Corps of Engineers and the Tennessee Valley Authority are used to predict the downstream water levels resulting from a dam breach (Refs. 7, 11, 16, 17 and 18). First-time l 2.4.4-2 Rev. 2 - July 1981 use of other models will require complete model description and documentation. Acceptance of the model (and subsequent analyses) is based on the staff review of model theory, available verification, and application. Where other than instantaneous failure is assumed, the conservatism of the rate of failure and shape of the breach should be well documented. A determination of the peak flow rate and water level at the site for the worst possible combination of dam failures and a summary analysis (that substantiates the condition as the critical permutation) must be presented, along with a description (and the bases) of all coefficients and methods used. Also, the effects of other concurrent events on plant safety, such as blockage of the river and water- borne missiles, must be considered. For SAR Sections 2.4.4.2 (Unsteady Flow Analysis of Potential Dam Failures) and 2.4.4.3 (Water Level at Plant Site): The effects of coincident and antecedent flood flows (or low flows for downstream structures) on initial pool levels must be considered. Use of the methods given in References 4 or 6 is acceptable for determination of initial pool levels. Depending upon esti- mated failure modes and the elevation difference between plant grade and normal river levels, it may be acceptable to use conservative simplified procedures to estimate flood levels at the site. Where calculated flood levels using simplified methods are at or above plant grade and using assumptions which cannot be demonstrated as conservative, it will be necessary to use unsteady flow methods to develop flood levels at the site. References 11 and 12 are acceptable methods; however, other programs would be acceptable with