NEA press room

25 Years After the Chernobyl Accident

On 26 April 1986, a major accident occurred at the Chernobyl nuclear power plant in the former Ukrainian Soviet Socialist Republic resulting in the evacuation of over 100 000 people within a 30-km radius of the site.

Approximately 600 000 emergency crew “liquidators” were engaged to stabilise the situation and to carry out clean-up operations. The accident resulted in the deaths of 31 liquidators and caused serious radiation effects to 140 others. Over 110 600 km2 of land in the former Soviet Union was contaminated with Caesium-137 (Cs-137) ranging from 40 kilobecquerels per square metre (kBq/m2) to over 1 500 kBq/m2. The level of Cs-137 contamination in affected areas will most likely be measurable for over 200 years or more.

The effects of this accident are still felt today. Almost 300 000 people continue to live in contaminated territories in what are now the Russian Federation, Ukraine and Belarus. Over 5 000 cases of thyroid cancer have since appeared in children exposed to iodine-131 (I-131) by drinking contaminated milk at the time of the accident. Fifteen of these children died as a result of their disease. Areas as far away as Norway and the United Kingdom remain contaminated and fall under grazing restriction for sheep and reindeer.

Over the last 25 years, the OECD Nuclear Energy Agency (NEA) and its member countries have worked with authorities and populations in the most affected areas to understand how to better address the radiological and social consequences of such a large-scale accident.  This work has included the organisation and assessment of 8 large-scale International Nuclear Emergency Exercises (INEX) involving each time 20 to 50 countries and 3 to 7 international organisations. The results of these exercises have been used by NEA member countries and other international organisations to improve national emergency response planning and the effectiveness of preparedness organisations.

Experience from the Chernobyl accident and from INEX demonstrates the importance of emergency planning and preparedness for the urgent phase of a nuclear or radiological accident and for the longer-term management of accident consequences. Engagement with affected populations and other stakeholders is key to formulating recovery strategies that can address the countless issues that can occur as a result of such an accident, including clean-up strategy, long-term health monitoring and returning evacuees to their homes.
Though the worst-case public health issues have not materialised, affected communities continue to deal with the consequences 25 years after the Chernobyl accident. While recent reports from the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) show that thyroid cancer in children exposed at the time has dramatically increased, they do not show any increase in cancer, leukaemia or other radiation-related illnesses in the affected areas. Contamination levels remain high and these communities require ongoing support from organisations such as the United Nations Development Program (UNDP).

The NEA continues to support assistance efforts to those affected by the Chernobyl accident and will continue to help its member countries improve nuclear and radiological emergency response capabilities. Experience gained since the Chernobyl accident will be invaluable in assisting the Japanese to recover from the Fukushima accident.

Related NEA reports and publications

Stakeholders and Radiological Protection:Lessons from Chernobyl 20 Years After Société civile et radioprotection : les enseignements de Tchernobyl, 20 ans après
A Report by the Committee on Radiation Protection and Public Health (CRPPH)
This report highlights the importance of involving local stakeholders in the long-term, post-recovery phase. The intervening twenty years of rehabilitation has shown that the active engagement of radiation protection professionals with the affected people has helped to effectively improve the living conditions in the contaminated territories. Integrating radiation protection measures into the daily lives of farmers and parents has allowed them to manage both their own radiation exposures and those of their families.

International Nuclear Law in the Post-Chernobyl Period Le droit nucléaire international après Tchernobyl
This report demonstrates how the accident heightened awareness of the need to improve the international legal regime governing the peaceful uses of nuclear energy.

Chernobyl: Assessment of Radiological and Health Impact Tchernobyl: Évaluation de l’impact radiologique et sanitaire
2002 Update of Chernobyl: Ten Years On
The international radiological protection community performed a major status review of the situation around the damaged Chernobyl reactor on the 10-year anniversary of the accident. Since then, studies of the accident site and the contaminated territories continue to be undertaken, which have yielded new scientific results and highlighted important social and health aspects. This report is a complete update of the NEA's earlier publication, Chernobyl: Ten Years On. In particular, it offers the reader the most recent information on the significant new experience gained in the areas of emergency management, long-term environmental behaviour of radioactive materials and health effects. (2003)

Related links

NEA Press briefing, 11 April 2006

Other international organisations have published significant reports on aspects of Chernobyl, notably the IAEA and the WHO:

International Programme on the Health Effects of the Chernobyl Accident (IPHECA)
The WHO's International Programme on the Health Effects of the Chernobyl Accident (IPHECA) was established to support national programmes, monitor health consequences and indicate future work needed to ensure that maximum information is gained from this disaster.

IAEA: Chernobyl: 20 Years Later
From the In Focus series: Years after the Chernobyl nuclear power plant accident, people in the region still live with wildly varying reports about what impact the accident will have on their families' future health and the environment. The IAEA-initiated 'Chernobyl Forum' is working to give people in the affected villages greater certainty, by issuing factual, authoritative statements on the accident's health effects.

UNSCEAR Reports on the exposures and effects of the Chernobyl accident
UNSCEAR has been involved from early on in the assessment of radiation exposures and health effects.

The United Nations and Chernobyl

NEA Radiological protection programme

NEA Legal Affairs programme

NEA Press kit: International nuclear third party liability

Last updated: 22 April 2011