Two-Dimensional Embankment Breach Analysis

A two-dimensional embankment breach analysis was conducted to estimate the postulated worst case flood levels to support the combined operation and construction licensing of a nuclear power plant. A multi-dimensional hydrodynamic model, Delft3D-FLOW, was used to simulate flooding from an instantaneous breaching of the embankment of an on-site cooling reservoir with a surface area of about 7,000 acre (2,800 hectare) and an average height of 40 ft (12.2 m). The Delft3D-FLOW feature for solving rapidly varying flows ("Flooding scheme") was utilized for the analysis. The results capture the water level variation due to the initial flood wave impact on the safety-related power buildings and the subsequent quasi-steady state flooding conditions that prevail for a few minutes. Various tailwater conditions (including dry bed) were analyzed to determine the critical flood level to be used as the design basis for the safety related facilities of the nuclear power plant.