Cost-Effective Alternatives to Experimental Testing for 316(a)

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Introduction

Thermal effect issues from power plant discharges are becoming more prevalent in the United States, raising concerns for plant operators and drawing the attention of regulators, particularly as more climate change issues arise. Regional temperature variations and drought conditions are causing river and lake levels to decline and water temperatures to increase, which will affect plant performance if flow rates cannot be increased. Increased flow rates may be required to maintain proper condenser cooling and vacuums for turbine efficiency and, keep discharge temperatures below thermal discharge limits.

Increased flow rates, however, will also lead to higher impingement and entrainment rates, which are limited by the 316(b) regulation. As a result, there is a need in the power industry to revisit temperature criteria and standards, with a view to balancing plant performance issues with standards specified in EPA 316(a) (thermal discharge limits), and 316(b) (biological impact limits).

Kinectrics Services – 316(a)

Investigations / Studies

Kinectrics investigates thermal release from power plants using a state-of-science Computational Fluid Dynamics approach. ANASYS / CFX software is employed to provide a comprehensive three-dimensional hydrodynamic simulation of the mixing process involving a released thermal plume and its background environment.

This advanced modeling approach is capable of realistically depicting the effects of bathymetry on the mixing process, as well as the sinking nature of thermal plumes during the winter season.

For example, this method can be used to assess the major 316(a) issue of incipient lethal and sub-lethal effects on aquatic biota, primarily invertebrates (e.g. mussels) and fish, and correlating these findings with habitat use.

Kinectrics’ comprehensive environmental services cover field and lab studies / investigation into individual locations, and plant situations where temperature intolerance and avoidance measurements of fish are required. For example, a temperature increase may impact eggs and larval fish, with increasing temperatures resulting in early hatching and development of fish in discharge areas. Alternatively, it may seriously impede growth and survival of fish and / or endangered invertebrate mussel species utilizing habitat influenced by the discharge.

Effective solutions for 316(a) and 316(b)

Kinectrics can develop specific engineering solutions to reduce harmful temperature effects, enabling stations to eliminate impacts or reduce residual effects on aquatic life and remain within accepted regulatory limits. Kinectrics services include:

• Engineering solutions specific to plant infrastructures, e.g. diffuser systems, spray modules, and cooling towers (either helper systems, or mechanical wet or dry cooling)
• Modified pipe intake design to draw deeper cooler water (surface-drawn intakes)
• Solutions to prevent fish from entering station discharge
• Effective options developed for reducing 316(b) fish impingement mortality can also be applied to 316(a) situations. These include diversion technologies such as electric fields, acoustics, louvers, and other behavioral systems.
• Kinectrics is active in developing leading-edge technologies for both 316(a) and 316(b). Current projects include recently completed tests for a number of U.S. clients at the Vero Beach Marine Lab, on evaluating methods for preventing fish entry into station discharges, and lab assessment / field evaluation of a pipe-based insert of different configurations.

For more information contact:

Paul Patrick, Ph. D., 416.207.6000 x6277, paul.patrick@kinectrics.com

Darlene Ager, Ph. D.,  416.207.6000 x6864,  darlene.ager@kinectrics.com