Fukushima Daiichi nuclear accident

On 11 March 2011, a massive earthquake of magnitude 9.0 on the Richter scale jolted the eastern coast of Japan. An hour after the earthquake, a 14-15 m tsunami, as estimated at the Fukushima Daiichi site, hit the Pacific coastline and led to a terrible loss of lives (approximately 19 000 people died or remain unaccounted for). It also led to loss of all onsite power sources resulting in serious accidents at the three operating Fukushima Daiichi units, which were classified by the Japanese authorities as level 7 on the International Nuclear and Radiological Event Scale (INES).

The accidents at Fukushima Daiichi Units 1, 2 and 3 were the result of the loss of offsite power caused by the earthquake, coupled with the loss of onsite power and the ultimate heat sink caused by the tsunami. Without a source of electrical power, the systems and components used to keep the fuel in the reactors cooled were not able to function. Although the operator attempted to implement alternative measures to cool the fuel, ultimately they were unsuccessful in preventing the fuel from overheating and melting. In addition, hydrogen generated during the accidents collected within the reactor buildings and caused explosions in the upper portions of the Unit 1, 3 and 4 reactor buildings, with significant damage to the top floors and exposure of the spent fuel pools to the environment.

In response to this accident, NEA member countries decided to alter the work priorities of the NEA standing technical committees in order to assess the accident and to identify safety lessons.

Work is being carried out on:

In addition, the NEA has devoted significant efforts to directly supporting the technical needs of the Japanese government, with this assistance primarily focusing on 1) the recovery of land and decontamination, 2) the development and implementation of national reviews and stress tests and 3) enhancements to the regulatory infrastructure.

Nuclear regulation

Actions taken by regulatory bodies and international organisations following the Fukushima Daiichi nuclear accident
A repository of information from 23 countries as well as 4 regional and 3 international organisations on national response activities, stress tests reports and complementary assessments and activities to the stress tests.

NEA meets with Japanese officials to discuss nuclear safety regulatory organisations
17-18 January 2012 - An NEA team of international experts met in Tokyo with members of the Japanese Advisory Committee for Prevention of Nuclear Accidents and the special Japanese Task Force for the Reform of Nuclear Safety Regulations and Organisations to foster increased understanding of various national regulatory organisations and approaches to regulatory oversight of nuclear power facilities.

The Fukushima Accident: Insights and Approaches
8 June 2011 - Meeting of nuclear regulatory authorities of the G8, NEA member countries and other associated countries (Brazil, Bulgaria, India, Romania, South Africa and Ukraine) to discuss insights gained in relation to the accident and decide on appropriate follow-up actions at the international level.
Proceedings of the Forum on the Fukushima Accident: Insights and Approaches

New avenues for improving international nuclear safety
7 June 2011 - International ministerial meeting co-organised by the French Presidency of the G8 and the NEA, with 37 countries in attendance.

Nuclear safety and research

Accident tolerant fuels workshop
On 10-12 December 2012, the NEA Working Party on Scientific Issues of the Fuel Cycle organised an international workshop to share information and discuss technical and safety issues associated with the development of accident tolerant fuels for light water reactors.

NEA meets with Japanese nuclear safety authorities to discuss national safety reviews / stress tests
16-18 November 2011 – NEA experts met in Tokyo with the Japanese Nuclear and Industrial Safety Agency (NISA) and the Japan Nuclear Energy Safety Organisation (JNES) to foster a better understanding by NISA and JNES of other NEA member countries' post-Fukushima national safety reviews/stress tests, international guidance and review methodologies.

Crisis communication

NEA Working Group on Public Communication of Nuclear Regulatory Organisations (WGPC)
26-28 September 2011 – The WGPC held a special meeting to follow up on lessons learnt from the Fukushima Daiichi accident prepared for a Crisis Communication Workshop held in Madrid on 9-10 May 2012.

Radiological protection

International meetings on remediation and restoration of environments
3-4 February 2012 – The NEA co-organised two days of international meetings on The Experience and Technology of Russia, Ukraine and Other CIS Countries on Remediation and Restoration of Environments. The meetings provided opportunities for experts from zones most affected by the Chernobyl accident to share best practices in managing contaminated land.

Decontamination and recovery

International Symposium on Decontamination held in Fukushima, Japan
16 October 2011 – The Government of Japan, in co-operation with the International Atomic Energy Agency (IAEA), the OECD Nuclear Energy Agency (NEA), the Japan Atomic Energy Agency (JAEA) and the Japan Nuclear Energy Safety Organisation (JNES), held an International Symposium on Decontamination – Towards the Recovery of the Environment, in Fukushima, Japan.

Nuclear liability and compensation

Japan's Compensation System for Nuclear Damage As Related to the TEPCO Fukushima Daiichi Nuclear Accident
The NEA has prepared this publication in co-operation with the government of Japan to share Japan's recent experience in implementing its nuclear liability and compensation regime. The material presented in the publication should provide valuable insights for those wishing to better understand the regime applied to compensate the victims of the accident and for those working on potential improvements in national regimes and the international framework for third party nuclear liability.

Further information

OECD Nuclear Energy Agency (NEA) follow-up to the TEPCO Fukushima Daiichi nuclear accident
Extracts from NEA News
The NEA has undertaken a number of activities following the March 2011 accident at the Fukushima Daiichi nuclear power plant in Japan. This brochure contains three extracts from NEA News published in the months following the accident: Fukushima (what happened, consequence, follow-up), published June 2011; Fukushima: liability and compensation, published December 2011; and The NEA integrated response to the Fukushima Daiichi nuclear accident, published June 2012. Together these extracts help the reader to better understand the causes, consequences and importance of the NEA's response to the Fukushima Daiichi accident (2012).


Last reviewed: 8 March 2013