Modelling flood propagation in the service galleries of a nuclear power plant

Abstract

In the context of the stress tests that have to be applied to nuclear power plants, this work presents the study of the flooding processes of the service galleries of a nuclear plant caused by a hypothetical failure of some of the pipes of the Essential Services Water System (ESWS). To assess the flood propagation along the galleries, two-dimensional hydraulic modelling tools, based on the solution of the shallow water equations with the finite volume method, were used. Due to the complexity and special features of the geometry and hydraulic processes, when compared with more standard urban flood assessment works, several specific modules were developed. A relevant one is a new module to consider the effect of the occupation of the galleries on the advance of the waterfront. This module was developed and verified prior to being applied to a case study. The results show the suitability of the proposed methodology to be used as part of the stress tests to ensure high security standards of nuclear power plants.

Interpreting the Manning Roughness Coefficient in Overland Flow Simulations with Coupled Hydrological-Hydraulic Distributed Models

“…They range from 0.069 s/m 1/3 , corresponding to urban settlements, to 0.207 s/m 1/3 corresponding to forested area. All these values widely exceed the traditionally recommended values for hydraulic computations in artificial or natural channels and floodplains areas [38][39][40][81][82][83]. Figure 3a plots the hydrographs resulting from the aggregated approach (dashed line) and the distributed approach (continuous line).…”

Metodología para el análisis de rotura de presas con aterramiento mediante simulación con fondo móvil

“…Este incremento puntual de la capacidad del embalse por la movilización de sedimentos provoca también un incremento en el caudal punta y en el volumen del hidrograma (Figura 6). Este fenómeno se producirá de una manera más o menos acusada en función del tamaño de la presa, del caudal circulante por el río, la formulación de transporte de sedimentos empleada, el tamaño de partícula considerado y del tipo de rotura (rápida o lenta), así como el coeficiente de rugosidad del fondo escogido [24,31]. En el caso de estudio, la formulación de transporte de sedimentos de fondo empleada se encuentra del rango de aplicación del diámetro de partícula propuesto para las ecuaciones consideradas (0,002 a 0,03 m).…”

Efficient Design of Road Drainage Systems

“…Iber is a freely distributed 2D numerical tool (www.iberaula.com, accessed on 12 June 2021) initially developed for modeling hydrodynamic and sediment transport [19,[24][25][26][27][28] that solves the SWEs on irregular geometries using the finite volume method (FVM). The tool has been continuously enhanced since it was first presented in 2010, and now includes a series of modules for different fluvial and hydrological processes, such as rainfall-runoff transformation [29][30][31], water quality processes [32,33], large wood transport [34], physical habitat suitability assessment [35], the consideration of pressurized flow [36][37][38][39], and, more recently, non-Newtonian flows such as wood-laden flows [40] and snow avalanches [41,42].…”