TECHNICAL REPORTS SERIES No. 139 Earthquake Guidelines for Reactor Siting INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA, 1972 EARTHQUAKE GUIDELINES FOR REACTOR SITING The following Slates are Members of the International Atomic Energy Agency: AFGHANISTAN GUATEMALA PAKISTAN ALBANIA HAITI PANAMA ALGERIA HOLY SEE PARAGUAY ARGENTINA HUNGARY PERU AUSTRALIA ICELAND PHILIPPINES AUSTRIA INDIA POLAND BELGIUM INDONESIA PORTUGAL BOLIVIA IRAN ROMANIA BRAZIL IRAQ SAUDI ARABIA BULGARIA IRELAND SENEGAL BURMA ISRAEL SIERRA LEONE BYELORUSSIAN SOVIET ITALY SINGAPORE SOCIALIST REPUBLIC IVORY COAST SOUTH AFRICA CAMEROON JAMAICA SPAIN CANADA JAPAN SUDAN CEYLON JORDAN SWEDEN CHILE KENYA SWITZERLAND CHINA KHMER REPUBLIC SYRIAN ARAB REPUBLIC COLOMBIA KOREA, REPUBLIC OF THAILAND COSTA RICA KUWAIT TUNISIA CUBA LEBANON TURKEY CYPRUS LIBERIA UGANDA CZECHOSLOVAK SOCIALIST LIBYAN ARAB REPUBLIC UKRAINIAN SOVIET SOCIALIST REPUBLIC LIECHTENSTEIN REPUBLIC DENMARK LUXEMBOURG UNION OF SOVIET SOCIALIST DOMINICAN REPUBLIC MADAGASCAR REPUBLICS ECUADOR MALAYSIA UNITED KINGDOM OF GREAT EGYPT, ARAB REPUBLIC OF MALI BRITAIN AND NORTHERN EL SALVADOR MEXICO IRELAND ETHIOPIA MONACO UNITED STATES OF AMERICA FINLAND MOROCCO URUGUAY FRANCE NETHERLANDS VENEZUELA GABON NEW ZEALAND VIET-NAM GERMANY, FEDERAL REPUBLIC OF NIGER YUGOSLAVIA GHANA NIGERIA ZAIRE, REPUBLIC OF GREECE NORWAY ZAMBIA 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 195V. 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". © IAEA, 1972 Petmission to reproduce or translate the information contained in this publication may be obtained by writing to the International Atomic Energy Agency, Kärntner Ring 11, P.O. Box 590, A-1011 Vienna, Austria. Printed by the IAEA in Austria September 1972 TECHNICAL REPORTS SERIES No. 139 EARTHQUAKE GUIDELINES FOR REACTOR SITING A MANUAL PREPARED AS THE RESULT OF A PANEL ON EARTHQUAKE GUIDELINES FOR SELECTION OF REACTOR SITES HELD IN VIENNA, 22-26 JUNE 1970 INTERNATIONAL ATOMIC ENERGY AGENCY VIENNA, 1972 EARTHQUAKE GUIDELINES FOR REACTOR SITING IAEA, VIENNA, 1972 STI / DOC /10 /13 9 FOREWORD No factor of the many that have to be taken into account in the siting of nuclear plants has recurred so consistently in the International Atomic Energy Agency's siting missions as that of earthquakes. Therefore these Guidelines to the siting of nuclear plants in earthquake zones have been prepared to assist national authorities and others faced with this problem, to guide the members of the Agency's Safety Missions in their work, and to constitute the safety guidelines which should be applied to operations undertaken by Member States with the assistance of the Agency. These guidelines describe the geological, engineering and seismic factors which should be considered for a site and give guidance to the in- vestigations required to evaluate these factors. CONTENTS INTRODUCTION 1 DEFINITIONS 1 1. DESIGN EARTHQUAKE 2 1.1. INFORMATION AND INVESTIGATIONS 2 1. 1. 1. Historical data 2 1.1.2. Geological data 3 1.1.3. Engineering data 4 1.2. EVALUATION OF REGIONAL DESIGN EARTHQUAKE MOTION 6 1.2.1. Semi-statistical method 6 1.2.2. Fault and area activity analysis 7 1.2.3. Evaluation of rock motion 8 1.2.4. Minimum value of design earthquake 8 1. 3. MODIFICATION OF REGIONAL DESIGN EARTHQUAKE FOR PARTICULAR SITE 9 2. SURFACE FAULTING 9 2.1. GENERAL DISCUSSION 9 2.2. INVESTIGATION 10 2.3. EVALUATION 11 3. TSUNAMIS AND OTHER SEISMICALLY CAUSED WATER WAVES 11 3.1. DISCUSSION 11 3.1.1. Locally generated tsunamis 11 3.1.2. Distantly generated tsunamis 11 3.1.3. Locally generated waves 11 3. 1. 4. Local topography which might modify run-up .... 11 3.2. REQUIRED INVESTIGATION 12 3.2. 1. Tsunamis caused by historical earthquakes 12 3. 2. 2. Historical records on run-up heights, damage and local amplification 12 3. 2. 3. Geological investigation of possible local tsunamis 12 3.2.4. Water waves in a lake 12 3.3. EVALUATION 3. 3. 1. Nearby generated tsunamis 12 3.3.2. Distantly generated tsunamis 13 3.3.3. Coastal uplift and subsidence 13 3.3.4. Cooling water supply 13 4. OTHER DESIGN CONDITIONS 13 4.1. GENERAL PART 13 4.1.1. Foundation stability 13 4.1.2. Slope stabilities 14 4. 1. 3. Cooling water supply 14 4.2. REQUIRED INVESTIGATIONS 14 4.2.1. Investigations for foundation stability 14 4.2.2. Investigation for slope stability 15 4.2.3. Cooling water supply 15 4.3. EVALUATION 15 4.3.1. Evaluation of foundation stability 15 4.3.2. Evaluation of slope stability 16 4. 3. 3. Evaluation of cooling water supply adequacy 16 POSTSCRIPT 16 ANNEX: Earthquake intensity scales 17 BIBLIOGRAPHY 23 LIST OF PARTICIPANTS 25 INTRODUCTION The purpose of this document is to suggest guidelines for the selection or evaluation of a nuclear plant site in an earthquake region. These guidelines describe the geological, engineering and seismic factors which should be considered for a site and give guidance as to what investigations are required for an evaluation of these various factors. DEFINITIONS Regional design earthquake The regional design earthquake is the strongest earthquake which it is reasonable to expect in the general region where the site is located, neglecting features which are local to the specific site itself. The maximum acceleration, the maximum velocity and the vibration frequency content of the motion in the regional design earthquake are important characteristics in determining the effect of that earthquake on structures or items subjected to its motion. Site design earthquake The site design earthquake is the regional design earthquake, modified if necessary to take account of features local to the specific site. The modifications should include allowance for severe but possible motions not yet revealed by the regional history. The design and construction of all structures and equipment which are necessary to shut down the nuclear reactor and to maintain safe conditions, without undue risk to the health and safety of the public, should be such as to withstand the site design earth- quake without substantially exceeding the elastic limit, or with limited deformations, so that they will fulfil their required functions with an adequate margin of safety. Seismo-tectonic province A seismo-tectonic province is a spatial division of a continent charac- terized by a unity of the geological structural features contained therein. Faults , A fault is a fracture along which differential displacement of the adjacent earth materials has occurred parallel to the fracture plane. It is to be distinguished from other types of ground disruption which may be caused by vibratory motion, such as landsliding, fissuring, and cratering. Subsidiary faulting, branch or secondary faults, are often associated with a main through-going fault. 1 Branch faults generally show the same type of displacement as the main fault and either join it at the surface or can reasonably be inferred to do so in the subsurface. Secondary faults are separate spatially from the main fault but nevertheless most of them also have the same type of displacement as the main fault. Areas of extensive local faulting may also occur which are not clearly related to major through-going faults. Tsunamis A tsunami is a seismic sea wave generated by a vertical crustal defor- mation of the sea bottom in deep water associated with a large earthquake. Tsunamis are also generated by underwater volcanic explosions and land- slides. When the tsunami approaches the shore line the height of the water wave is sometimes substantially amplified by the shape or topography of the coast, particularly in bays. 1. DESIGN EARTHQUAKE 1.1. INFORMATION AND INVESTIGATIONS 1.1.1. Historical data Since the design earthquake is defined as the most severe which may be expected at the site, it is desirable to make use of historical records extending as far back as can be obtained. Many such records will naturally be of a descriptive type, e. g. number of houses destroyed or damaged. From such information a measure of the intensity of each earthquake may be obtained at the various points where records were made. It is not suggested that any particular scale of intensity should be employed, as it will be most convenient to keep whatever national or local scale has already been employed. Care should however be taken to adjust the derived figures of intensity to allow for changes in the type of structure which may have occurred as between earlier and later records. A compa- rison between various intensity scales has been included in Table IV of the Annex for convenience. The interpretation of such intensity figures may take various forms, and will be strongly affected by such factors as the number of years over which records are available, frequency of earthquakes and proportion of strong-motion records. It follows that any estimate of the maximum intensity of earthquake which may occur at the site will incorporate a degree of uncertainty which will vary from country to country. The first estimate of the design earthquake for the site may be a simple figure of maximum horizontal acceleration, derived from topo- graphical plotting of the calculated intensities, with interpolations made by the judgement and experience of the engineering seismologist. The intensity data, in conjunction with knowledge of faulting, may permit the determination of the epicentre and magnitude of each earthquake, using suitable methods for correlating the surface intensities which were observed. To help in arriving at an estimate of the intensity of the design earth- quake it is sometimes useful to plot the intensities of the recorded earth- 2 quakes at the site against the frequency of occurrence.