TECHNICAL REPORTS SERIES No. 202 Environmental Effects of Cooling Systems ^ffil INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA, 1980 ENVIRONMENTAL EFFECTS OF COOLING SYSTEMS The following States are Members of the International Atomic Energy Agency: AFGHANISTAN HOLY SEE PHILIPPINES ALBANIA HUNGARY POLAND ALGERIA ICELAND PORTUGAL ARGENTINA INDIA QATAR AUSTRALIA INDONESIA ROMANIA AUSTRIA IRAN SAUDI ARABIA BANGLADESH IRAQ SENEGAL BELGIUM IRELAND SIERRA LEONE BOLIVIA ISRAEL SINGAPORE BRAZIL ITALY SOUTH AFRICA BULGARIA IVORY COAST SPAIN BURMA JAMAICA SRI LANKA BYELORUSSIAN SOVIET JAPAN SUDAN SOCIALIST REPUBLIC JORDAN SWEDEN CANADA KENYA SWITZERLAND CHILE KOREA, REPUBLIC OF SYRIAN ARAB REPUBLIC COLOMBIA KUWAIT THAILAND COSTA RICA LEBANON TUNISIA CUBA LIBERIA TURKEY CYPRUS LIBYAN ARAB JAMAHIRIYA UGANDA CZECHOSLOVAKIA LIECHTENSTEIN UKRAINIAN SOVIET SOCIALIST DEMOCRATIC KAMPUCHEA LUXEMBOURG REPUBLIC DEMOCRATIC PEOPLE'S MADAGASCAR UNION OF SOVIET SOCIALIST REPUBLIC OF KOREA MALAYSIA REPUBLICS DENMARK MALI UNITED ARAB EMIRATES DOMINICAN REPUBLIC MAURITIUS UNITED KINGDOM OF GREAT ECUADOR MEXICO BRITAIN AND NORTHERN EGYPT MONACO IRELAND EL SALVADOR MONGOLIA UNITED REPUBLIC OF ETHIOPIA MOROCCO CAMEROON FINLAND NETHERLANDS UNITED REPUBLIC OF FRANCE NEW ZEALAND TANZANIA GABON NICARAGUA UNITED STATES OF AMERICA GERMAN DEMOCRATIC REPUBLIC NIGER URUGUAY GERMANY, FEDERAL REPUBLIC OF NIGERIA VENEZUELA GHANA NORWAY VIET NAM GREECE PAKISTAN YUGOSLAVIA GUATEMALA PANAMA ZAIRE HAITI PARAGUAY ZAMBIA PERU The Agency's Statute was approved on 23 October 1956 by the Conference on the Statute of the IAEA held at United Nations Headquarters, New York; it entered into force on 29 July 1957. The Headquarters of the Agency are situated in Vienna. Its principal objective is "to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world". (C) IAEA, 1980 Permission to reproduce or translate the information contained in this publication may be obtained by writing to the International Atomic Energy Agency, Wagramerstrasse 5, P.O. Box 100, A-1400 Vienna, Austria. Printed by the IAEA in Austria December 1980 TECHNICAL REPORTS SERIES No. 202 ENVIRONMENTAL EFFECTS OF COOLING SYSTEMS REPORT OF A CO-ORDINATED RESEARCH PROGRAMME ON PHYSICAL AND BIOLOGICAL EFFECTS ON THE ENVIRONMENT OF COOLING SYSTEMS AND THERMAL DISCHARGES FROM NUCLEAR POWER STATIONS INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA, 1980 ENVIRONMENTAL EFFECTS OF COOLING SYSTEMS IAEA, VIENNA, 1980 STI/DOC/10/202 ISBN 92-0-125380-X FOREWORD Since the International Atomic Energy Agency published in 1974 Thermal Discharges at Nuclear Power Stations (Technical Reports Series No. 155), much progress has been made in the understanding of phenomena related to thermal discharges. Many studies have been performed in Member States and from 1973 to 1978 the IAEA sponsored a co-ordinated research programme on 'Physical and Bio- logical Effects on the Environment of Cooling Systems and Thermal Discharges from Nuclear Power Stations'. Seven laboratories from Canada, the Federal Republic of Germany, India and the United States of America were involved in this programme, and a lot of new information has been obtained during the five years' collaboration. The progress of the work was discussed at annual co-ordination meetings and the results are presented in the present report. It complements the previous report mentioned above as it deals with several questions that were not answered in 1974. With the conclusion of this co-ordinated programme, it is obvious that some problems have not yet been resolved and that more work is necessary to assess completely the impact of cooling systems on the environment. It is felt, however, that the data gathered here will bring a substantial contribution to the under- standing of the subject. The IAEA is grateful to J.W. McMahon (Atomic Energy of Canada Ltd), W. Schikarski (Kernforschungszentrum Karlsruhe), P. Kamath (Bhabha Atomic Research Centre), W. Wrenn and C. Voigtlander (Tennessee Valley Authority), C. Coutant (Oak Ridge National Laboratory), M. Schneider (Battelle, Pacific Northwest Laboratories) and S. Spigarelli (Argonne National Laboratory) for their outstanding contributions to the programme. CONTENTS CHAPTER 1: INTRODUCTION (L. Farges) 1 CHAPTER 2: PHYSICAL AND CHEMICAL CONSIDERATIONS 3 2.1. Mathematical and physical models of heat dissipation: Aquatic system models (W. Rodi) 3 2.2. Chlorine models (J. Mattice) 12 2.3. Heat exchange between water and atmosphere (W. Schikarski, G. Hoffmann) 26 2.4. Cooling tower plume modelling (W. Schikarski) 30 CHAPTER 3: BIOLOGICAL AND ECOLOGICAL CONSIDERATIONS .. 33 3.1. Gas dynamics 33 3.1.1. Oxygen production by photosynthetic activity of algae and macrophytes (M. Wunderlich) 33 3.1.2. Oxygen consumption by bacteria (M. Wunderlich) 35 3.1.3. Gas bubble disease in fish (M. Schneider) 38 3.2. Cooling system effects on plankton (/. McMahon, A. Docherty, S. Gentner) 49 3.3. Biological effects of thermal discharges on benthos (C. Voigtlander) 56 3.4. Effects of cooling water intakes on fish populations: Entrainment and impingement (C. Voigtlander) 60 3.5. Influence of temperature and other cooling-system factors on fish behaviour (S. Spigarelli) 79 3.6. Growth and energetics (C. Coutant) 96 3.7. Predator-prey interactions (C. Coutant, P. Kamath) 107 3.8. Influences of cooling systems on diseases and parasites 118 3.8.1. Diseases and parasites of aquatic organisms (P. Kamath, S. Spigarelli) 118 3.8.2. Human diseases 121 3.8.2.1. Pathogenic amoebae (C. Coutant) 121 3.8.2.2. Human disease organisms in aerosols from cooling towers and cooling-sprays (B.G.Lewis) 124 3.9. Combined effects (M. Schneider) 129 3.10. Adaptation capability (C. Coutant) 134 3.11. Effects of closed cycle cooling (C. Coutant, F. G. Taylor) 141 3.12. Effects of chlorine on aquatic organisms (/. Mattice) 148 CHAPTER 4: SPECIAL TOPICS 169 4.1. Tropics 169 4.1.1. Biological effects of thermal discharges in tropical regions (J. McMahon) 169 4.1.2. Thermal monitoring experiences in coastal waters and reservoirs (P. Kamath) 172 4.2. Ecosystem stress and cooling systems (S. Spigarelli, C. Coutant) 175 CHAPTER 5: PERSPECTIVES 185 5.1. Retrospective comments (S. Spigarelli, C. Voigtlander, M.Schneider) 185 5.2. Critical choices for energy conservation in power plant cooling (C. Coutant) 188 5.3. Beneficial uses of reject heat (C. Coutant) 190 5.4. Information sources (C. Coutant) 192 List of participants in the programme 195 Chapter 1 INTRODUCTION All steam-powered electrical generating plants, whether fired by fossil or by nuclear fuel, have a common potential problem in their need for important quantities of water which is heated and released to the environment. Perhaps no other single environmental factor affects aquatic life as profoundly or in such a pervasive manner as temperature. Unfavourable temperature may affect reproduction, growth, survival of larval forms, juveniles and adults, and all the life processes necessary to maintain a healthy state. Thus, it is not surprising that such bodies as regulatory authorities, health ministries and environmental agencies support biological and ecological studies required for the understanding of the complex phenomena connected with pumping, heating and discharging large quantities of water. These studies are necessary for assessing the possible damage to aquatic life in waters receiving thermal discharges. The various aspects of this subject have been investigated in the work undertaken for the present publication, which complements and extends the work published by the IAEA in 1974 in Technical Reports Series No. 155. In particular, physical and chemical aspects of cooling systems have been studied through physical and mathematical models for heat dissipation, heat exchanges and cooling tower plumes. Work on gas dynamics reported here includes considerations on oxygen production by photosynthetic activity, oxygen consumption by bacteria and gas bubble disease in fish. Investigations on biological and ecological aspects deal with the effects of cooling water intakes on plankton and fish population, the influence of thermal discharges on benthos, migration behaviour, growth, predator prey and host/parasite relationships. It has been observed that new diseases appear with the proliferation of parasites. Combined and synergetic effects as well as adaptation capability of species have also been studied. As insufficient attention has been given in the past to the environmental effects of closed cycle cooling, a section briefly reviews recent reports on the effects such cooling systems may have. Differences in interpretation of the effects of chlorine on aquatic organisms lead to disputes between those responsible for utilities and environmentalists; a section deals with this important topic. It has been suggested that the destruction or alteration of marine com- munities by heated effluents is greatest in tropical regions. A survey of field and laboratory studies conducted both in Florida and in India is presented in the present report. 1 2 INTRODUCTION Intensive investigations of certain projected impacts of power-plant cooling have provided answers useful for resolving some issues. In some cases, the predicted impact, although accepted as theoretically relevant, has been found to occur only insignificantly. In other cases, enough knowledge has been gained for practical guidelines to be formulated that ensure the adequate prevention of the impact through appropriate siting, design or operation