T h e F u k u s h i m a D a i i c h i A c c i d e n t The Fukushima Daiichi Accident R Report by the Director General e p o r t b y t h e D i r e c t o r G e n e r a l PO Box 100, Vienna International Centre 1400 Vienna, Austria 1 Printed in Austria GC(59)/14 ISBN 978–92–0–107015–9 (set) THE FUKUSHIMA DAIICHI ACCIDENT REPORT BY THE DIRECTOR GENERAL The following States are Members of the International Atomic Energy Agency: AFGHANISTAN GERMANY OMAN ALBANIA GHANA PAKISTAN ALGERIA GREECE PALAU ANGOLA GUATEMALA PANAMA ARGENTINA GUYANA PAPUA NEW GUINEA ARMENIA HAITI PARAGUAY AUSTRALIA HOLY SEE PERU AUSTRIA HONDURAS PHILIPPINES AZERBAIJAN HUNGARY POLAND BAHAMAS ICELAND PORTUGAL BAHRAIN INDIA QATAR BANGLADESH INDONESIA REPUBLIC OF MOLDOVA BELARUS IRAN, ISLAMIC REPUBLIC OF ROMANIA BELGIUM IRAQ RUSSIAN FEDERATION BELIZE IRELAND RWANDA BENIN ISRAEL SAN MARINO BOLIVIA, PLURINATIONAL ITALY SAUDI ARABIA STATE OF JAMAICA SENEGAL BOSNIA AND HERZEGOVINA JAPAN SERBIA BOTSWANA JORDAN SEYCHELLES BRAZIL KAZAKHSTAN SIERRA LEONE BRUNEI DARUSSALAM KENYA SINGAPORE BULGARIA KOREA, REPUBLIC OF SLOVAKIA BURKINA FASO KUWAIT SLOVENIA BURUNDI KYRGYZSTAN SOUTH AFRICA CAMBODIA LAO PEOPLE’S DEMOCRATIC SPAIN CAMEROON REPUBLIC SRI LANKA CANADA LATVIA SUDAN CENTRAL AFRICAN LEBANON SWAZILAND REPUBLIC LESOTHO SWEDEN CHAD LIBERIA SWITZERLAND CHILE LIBYA SYRIAN ARAB REPUBLIC CHINA LIECHTENSTEIN TAJIKISTAN COLOMBIA LITHUANIA THAILAND CONGO LUXEMBOURG THE FORMER YUGOSLAV COSTA RICA MADAGASCAR REPUBLIC OF MACEDONIA CÔTE D’IVOIRE MALAWI TOGO CROATIA MALAYSIA TRINIDAD AND TOBAGO CUBA MALI TUNISIA CYPRUS MALTA TURKEY CZECH REPUBLIC MARSHALL ISLANDS UGANDA DEMOCRATIC REPUBLIC MAURITANIA OF THE CONGO MAURITIUS UKRAINE DENMARK MEXICO UNITED ARAB EMIRATES DJIBOUTI MONACO UNITED KINGDOM OF DOMINICA MONGOLIA GREAT BRITAIN AND DOMINICAN REPUBLIC MONTENEGRO NORTHERN IRELAND ECUADOR MOROCCO UNITED REPUBLIC EGYPT MOZAMBIQUE OF TANZANIA EL SALVADOR MYANMAR UNITED STATES OF AMERICA ERITREA NAMIBIA URUGUAY ESTONIA NEPAL UZBEKISTAN ETHIOPIA NETHERLANDS VENEZUELA, BOLIVARIAN FIJI NEW ZEALAND REPUBLIC OF FINLAND NICARAGUA VIET NAM FRANCE NIGER YEMEN GABON NIGERIA ZAMBIA GEORGIA NORWAY ZIMBABWE 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’’. THE FUKUSHIMA DAIICHI ACCIDENT REPORT BY THE DIRECTOR GENERAL GC(59)/14 FOREWORD By Yukiya Amano Director General This report presents an assessment of the causes and consequences of the accident at the Fukushima Daiichi nuclear power plant in Japan, which began on 11 March 2011. Caused by a huge tsunami that followed a massive earthquake, it was the worst accident at a nuclear power plant since the Chernobyl disaster in 1986. The report considers human, organizational and technical factors, and aims to provide an understanding of what happened, and why, so that the necessary lessons learned can be acted upon by governments, regulators and nuclear power plant operators throughout the world. Measures taken in response to the accident, both in Japan and internationally, are also examined. The immense human impact of the Fukushima Daiichi accident should not be forgotten. More than 100 000 people were evacuated because of the release of radionuclides to the environment. At the time of writing, in 2015, many of them were still unable to return to their homes. I visited the Fukushima Daiichi plant a few months after the accident and saw for myself the powerful and destructive impact of the tsunami. It was a shocking and sobering experience. But I was deeply impressed by the courage and dedication of those workers and managers who remained at their posts after the tsunami struck and who struggled, in appalling conditions, to bring the stricken reactors under control. They had to improvise a response in circumstances for which they had not been trained, often lacking appropriate equipment. They deserve our respect and admiration. A major factor that contributed to the accident was the widespread assumption in Japan that its nuclear power plants were so safe that an accident of this magnitude was simply unthinkable. This assumption was accepted by nuclear power plant operators and was not challenged by regulators or by the Government. As a result, Japan was not sufficiently prepared for a severe nuclear accident in March 2011. The Fukushima Daiichi accident exposed certain weaknesses in Japan’s regulatory framework. Responsibilities were divided among a number of bodies, and it was not always clear where authority lay. There were also certain weaknesses in plant design, in emergency preparedness and response arrangements and in planning for the management of a severe accident. There was an assumption that there would never be a loss of all electrical power at a nuclear power plant for more than a short period. The possibility of several reactors at the same facility suffering a crisis at the same time was not considered. And insufficient provision was made for the possibility of a nuclear accident occurring at the same time as a major natural disaster. Since the accident, Japan has reformed its regulatory system to better meet international standards. It gave regulators clearer responsibilities and greater authority. The new regulatory framework will be reviewed by international experts through an IAEA Integrated Regulatory Review Service mission. Emergency preparedness and response arrangements have also been strengthened. Other countries responded to the accident with measures that included carrying out ‘stress tests’ to reassess the design of nuclear power plants against site specific extreme natural hazards, installing additional backup sources of electrical power and supplies of water, and strengthening the protection of plants against extreme external events. Although nuclear safety remains the responsibility of each individual country, nuclear accidents can transcend national borders. The Fukushima Daiichi accident underlined the vital importance of effective international cooperation. The IAEA is where most of that cooperation takes place. Our Member States adopted the IAEA Action Plan on Nuclear Safety a few months after the accident and have been implementing its far-reaching provisions to improve global nuclear safety. The IAEA, which provided technical support and expertise to Japan after the accident and shared information about the unfolding crisis with the world, has reviewed and improved its own arrangements for responding to a nuclear emergency. Our role during a nuclear emergency has been expanded to include providing analysis of its potential consequences and presenting possible scenarios on how a crisis could develop. IAEA safety standards embody an international consensus on what constitutes a high level of safety. They were reviewed after the accident by the Commission on Safety Standards. A few amendments were proposed and adopted. I encourage all countries to fully implement IAEA safety standards. IAEA peer reviews have a key role to play in global nuclear safety, enabling countries to benefit from the independent insights of leading international experts, based on the common reference frame of the IAEA safety standards. They address issues such as operational safety at nuclear power plants, the effectiveness of nuclear regulators and the design of nuclear power plant sites against specific hazards. We have strengthened our peer review programme since the accident and will continue to do so. I am confident that the legacy of the Fukushima Daiichi accident will be a sharper focus on nuclear safety everywhere. I have seen improvements in safety measures and procedures in every nuclear power plant that I have visited. There is widespread recognition that everything humanly possible must be done to ensure that no such accident ever happens again. This is all the more essential as global use of nuclear power is likely to continue to grow in the coming decades. There can be no grounds for complacency about nuclear safety in any country. Some of the factors that contributed to the Fukushima Daiichi accident were not unique to Japan. Continuous questioning and openness to learning from experience are key to safety culture and are essential for everyone involved in nuclear power. Safety must always come first. I express my gratitude to the experts from many countries and international organizations who contributed to this report, and to my colleagues at the IAEA who drafted and reviewed it. I hope that the report, and the accompanying technical volumes, will prove valuable to all countries that use, or plan to use, nuclear power in their continuous efforts to improve safety. ACKNOWLEDGEMENTS Financial assistance was provided by Canada, Japan, the Russian Federation, the United Kingdom and the United States of America. In-kind contributions were received from Argentina, Australia, Belarus, Brazil, Canada, China, Cuba, the Czech Republic, Finland, France, Germany, Ghana, Iceland, India, Indonesia, Israel, Italy, Japan, the Republic of Korea, Malaysia, Mexico, Morocco, the Netherlands, New Zealand, Norway, Pakistan, the Philippines, Poland, the Russian Federation, Slovakia, South Africa, Spain, Sweden, Switzerland, the Syrian Arab Republic, Turkey, Ukraine, the United Arab Emirates, the United Kingdom, the United Republic of Tanzania and the United States of America. In-kind contributions were also received from the European Commission, the Food and Agriculture Organization of the United Nations, the International Commission on Radiological Protection, the International Labour Organization, the International Nuclear Safety Group, the OECD Nuclear Energy Agency, the United Nations Scientific Committee on the Effects of Atomic Radiation, the World Association of Nuclear Operators and the World Meteorological Organization. The Government of Japan provided invaluable support by making available a considerable amount of information, arranging for Japanese experts to support the work on the report and ensuring logistical assistance for bilateral meetings in Japan. The United Nations Scientific Committee on the Effects of Atomic Radiation supported the IAEA by sharing the relevant database of references from its 2013 report and allowing information and figures from the report to be reproduced. The IAEA thanks the large number of experts who were involved in this report. It is the result of the dedicated efforts of many people. All participants listed at the end of this report made valuable contributions, but a particularly heavy load was borne by the Co-Chairs and coordinators of the working groups. The efforts of many expert reviewers, including members of the International Technical Advisory Group, are also gratefully acknowledged. CONTENTS EXECUTIVE SUMMARY .................................................................................................................................... 1 SUMMARY REPORT ......................................................................................................................................... 19 1. INTRODUCTION ...................................................................................................................................... 19 1.1. THE REPORT ON THE FUKUSHIMA DAIICHI ACCIDENT ..................................................... 20 2. THE ACCIDENT AND ITS ASSESSMENT ............................................................................................. 23 2.1. DESCRIPTION OF THE ACCIDENT ............................................................................................. 23 2.1.1. Initiating event and response ................................................................................................ 23 2.1.2. Progression of the accident .................................................................................................. 33 2.1.3. Stabilization efforts .............................................................................................................. 44 2.2. NUCLEAR SAFETY CONSIDERATIONS .................................................................................... 48 2.2.1. Vulnerability of the plant to external events ........................................................................ 48 2.2.2. Application of the defence in depth concept ........................................................................ 52 2.2.3. Assessment of the failure to fulfil fundamental safety functions ......................................... 55 2.2.4. Assessment of beyond design basis accidents and accident management............................ 59 2.2.5. Assessment of regulatory effectiveness ............................................................................... 63 2.2.6. Assessment of human and organizational factors ................................................................ 67 2.3. OBSERVATIONS AND LESSONS ................................................................................................ 70 3. EMERGENCY PREPAREDNESS AND RESPONSE .............................................................................. 74 3.1. INITIAL RESPONSE IN JAPAN TO THE ACCIDENT ................................................................ 75 3.1.1. Notification .......................................................................................................................... 76 3.1.2. Mitigatory actions ................................................................................................................ 77 3.1.3. Management of the emergency ............................................................................................ 79 3.2. PROTECTING EMERGENCY WORKERS ................................................................................... 81 3.2.1. Protection of personnel at the plant following the earthquake and tsunami ......................... 82 3.2.2. Protective measures for emergency workers ........................................................................ 82 3.2.3. Designation of emergency workers ...................................................................................... 83 3.2.4. Medical management of emergency workers ....................................................................... 84 3.3. PROTECTING THE PUBLIC .......................................................................................................... 84 3.3.1. Urgent protective actions and relocation .............................................................................. 85 3.3.2. Protective actions relating to food, drinking water and agriculture ...................................... 89 3.3.3. Public information ................................................................................................................ 90 3.3.4. International trade ................................................................................................................ 91 3.3.5. Waste management in the emergency phase ........................................................................ 91 3.4. TRANSITION FROM THE EMERGENCY PHASE TO THE RECOVERY PHASE AND ANALYSES OF THE RESPONSE .................................................................................................. 92 3.4.1. Transition from the emergency phase to the recovery phase ............................................... 92 3.4.2. Analyses of the response ...................................................................................................... 93 3.5. RESPONSE WITHIN THE INTERNATIONAL FRAMEWORK FOR EMERGENCY PREPAREDNESS AND RESPONSE .............................................................................................. 94 3.6. OBSERVATIONS AND LESSONS ................................................................................................ 96