Vertical Diffusion in a Stratified Cooling Lake
Publication: Journal of Hydraulic Engineering
Volume 113, Issue 3
Abstract
Lake Anna, a reservoir of 3,900 ha and 21 m maximum depth, provides cooling water for the two‐unit North Anna Nuclear Power Station in Virginia. Using the flux‐gradient method, vertical diffusivities in the lower layers of Lake Anna are computed from seven years of temperature data dating back to before plant operation. Results indicate strong dependence of vertical mixing on condenser flow rate with average summertime diffusivities below the surface layer ranging from for conditions of two‐unit operation and from for conditions of zero to one unit operation. Vertical diffusion is parameterized as a calibrated function of condenser flow rate, wind speed, and a characteristic vertical density difference. A numerical model employing this parameterization gives good agreement between measured and predicted vertical temperature profiles during separate validation tests.
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Copyright © 1987 ASCE.
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Published online: Mar 1, 1987
Published in print: Mar 1987
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