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Ballast water systems in large LNG carriers are essential for proper operations and stability. Water withdrawn from the surrounding environment to supply to the ballast can pose entrainment and impingement risk to the resident fish population. Quantification of these risks and the net effect on population is usually quite challenging and complex. V...
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... density data were separated into different zones along the length of the Delaware River and, for purposes of this case study, it was assumed that these densities did not vary vertically and were composites of all trawls in each zone; however, the hydrodynamic model was divided into three vertical zones: epilimnion, metalimnion and hypolimnion. Only four zones (8)(9)(10)(11) around the import terminal were considered as they covered a region of 25 miles downstream and 30 miles upstream (see Figure 3). The entrainable population within these four zones is shown in Table 1. ...
Citations
... An empirical model has been applied for evaluating entrainment of aquatic organisms in NPPs ever since the 1970s (Eraslan et al., 1975;Swartzman et al., 1977;Boreman et al., 1978). With the development of computational fluid dynamics, numerical models became a useful tool for predicting blockages of water intake structures of NPPs through calculating the probability of biological impingement (Zhang et al., 1992;Prakash et al., 2014). In this paper, a high-resolution, non-structured, three-dimensional numerical model, the TELEMAC-3D, was used to systematically and quantitatively study the factors influencing the probability of biological impingement, including distance to water intake structure, quantity of water intake, tide pattern, tidal current direction, and water depth. ...
Invasion or aggregation of marine organisms in cooling water intake systems (CWIS) has gradually become an important problem affecting the safety of nuclear power plants with environmental and climate changes. In this study, a 3-dimensional numerical model (TELEMAC-3D) was used to determine the impingement probability in a typical nuclear power plant with a once-through cooling system, and the effect on CWIS safety. The factors controlling impingement probability were also analyzed. Results show that (1) impingement probability decreased rapidly with an increase in distance from the CWIS. In addition, the distance of the impingement effect of a nuclear power plant with six units was mainly within 1 km of the CWIS. (2) Impingement probability increased with water withdrawal, and as distance to the CWIS increased, the increase in probability increased. (3) Generally, an increase in tide strength led to a decrease impingement probability. (4) Near the CWIS, the impingement probabilities of areas upstream or downstream of the CWIS along the tidal flow direction were much higher than those not in those areas. (5) An increase in water depth significantly reduced impingement probability. When the water depth of the CWIS increased from 5 m to 15 m, impingement probability was reduced up to 30%. Based on the above findings, the following suggestions were made to minimize the impingement effects on CWIS safety: first, the CWIS of coastal nuclear power plants should be set in an area with low aquatic biomass, strong tides, deep water, and few surface species within the range of 1 km, and second, the amount of cooling water withdrawal or velocity should be reduced as much as possible.
... To that end, there has been extensive research on trying to reduce sturgeon impingement and entrainment. For example, Prakash et al. (2014) used swimming capabilities to suggest that Atlantic and shortnose sturgeon can swim well enough to move away from the potential zone of influence of ship ballast intakes and avoid impingement. However, this does not consider whether the fish can detect the threat in time to swim away. ...
Acipenserids (sturgeons) live in large rivers and lakes in North America and Eurasia, where many species and populations are considered imperiled. One of the most pervasive threats across the global range of sturgeon is water resource development (e.g., hydropower dams, water intakes for irrigation, industrial use, or human consumption). We report on the outcome of a literature review focused on interactions between sturgeon and water resource development. We focused on the persistent issue of dam passage (both upstream and downstream), impingement, and entrainment, which are all relevant issues for both existing and planned facilities. We discuss aspects of sturgeon sensory physiology, and how knowledge of sensory physiology can be used for behavioural guidance. We also consider how the swimming ability and style of sturgeon is relevant for passage. Most of the literature emanated from research on just a few species (especially lake sturgeon, white sturgeon, green sturgeon, and shortnose sturgeon). Although there are several examples of apparent “success stories” (e.g., successful upstream fish passage, efforts to reduce impingement and entrainment), there are also many failures, and such examples are likely under-reported. Without significant investments in solutions-oriented research related to sturgeon-water resource development interactions, we submit that fish passage, entrainment and impingement problems for acipenserids will remain. There is a need for research that spans life-stages, compares different species, and considers how passage, entrainment, and impingement influence demography. Further, there is a need for investment into evidence-based implementation of mitigation infrastructure and management strategies to ensure conservation needs of sturgeons are adequately considered.
