Northwest Fisheries Science Center

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Document Type: Report
Center: NWFSC
Document ID: 9255
Title: Thermal effects of an important zooplankter Daphnia pulex on the Columbia River
Author/Editor: Donovan R. Craddock
Year: 1970
Institution: Technical Advisory Committee, Columbia River Thermal Effects Study.  Bureau of Commercial Fisheries, Seattle Biological Laboratory

A review of Pacific Northwest power needs made by the Bonneville Power Administration emphasized that electrical power demand in the region will more than triple in the next 20 years and that by the mid 1970s, a thermal plant of 1,000 Megawatts (MW) capacity or more will be required each year to meet demand.  The installed thermal generating capacity in the Pacific Northwest at the present totals only a little over 1,000 MW, but is predicted to increase to 15,000 MW by 1987.  The additional power wil1 be produced primarily by thermal nuclear plants, which require 2.0 cfs of cooling water per MW of power produced.  This quantity of water, approximately 30,000 cfs, could be heated 16-20°F (9-11°C) above ambient before being returned to the rivers, bays, and estuaries of the Pacific Northwest.  Four of the thermal nuclear electric plants planned for the region by 1990 are on the Columbia River and represent a production potential of 9,000 MW.

The effect of heat which must be absorbed by the receiving waters is of major concern to those interested in the preservation of the aquatic environment and its biota.  The aquatic flora and fauna will suffer the impact of this waste heat in three areas:

  1. In the condensers where sudden temperature increases occur
  2. Near the discharge tubes or ports in the river where sudden temperature increases occur between the plumes and the ambient river waters
  3. Throughout the entire receiving body of water after diffusion

These last two conditions can be mitigated by off-river cooling, e.g., cooling ponds or cooling towers.