NEA Mandates and Structures

Ad Hoc Expert Group on the Estimation of Potential Losses Due to Nuclear Accidents, Liability Issues and Their Impact on Electricity Costs (COSTNA)

Chair(s): Neil HIGGINS, United Kingdom
Secretary:  Aditi VERMA
Vice-Chair(s): Stefan HIRSCHBERG, Switzerland
Member(s):All NEA member countries
Full participant(s): European Commission
Under the NEA Statute
Observer(s)(International Organisation): International Atomic Energy Agency (IAEA)
By agreement
Date of creation:01 January 2013
End of mandate:31 December 2021

Mandate (Document reference):

Mandate (Document extract):

Extract of document [NEA/NDC(2019)24]



Albeit remote, the risk of a severe nuclear accident cannot be reduced to zero, carrying the potential to cause grave consequences to the concerned nuclear site and, if offsite radiological releases are involved, the surrounding territory, with effects on the surrounding population and potential contamination of associated land. As experienced in the Chernobyl and Fukushima Daiichi accidents, direct and indirect costs can reach several per cents of the GDP and seriously affect the equilibrium of a country for some years. Direct and indirect consequences of the accident can also extend to other countries. That was the case during the Chernobyl accident, when many European countries experienced land contamination, with consequent restrictions on food consumption implemented across Europe. Another far-reaching effect caused to various degrees by the three severe accidents (Three Mile Island, Chernobyl and Fukushima Daiichi) has been the impact on energy choices of several countries and on the whole nuclear industry. ‘What are the “true” costs of a nuclear accident’ is therefore a complex and highly debated question.


As underlined in the previous NEA study, “Methodologies for Assessing the Economic Consequences of Nuclear Reactor Accidents”, the methodologies adopted, along with the cost elements these can consider and combine, greatly depend upon the objective of the cost study and the intended use of the resulting “accident cost” figures. For instance, only some cost elements will be considered from the perspective of accident management, while a proper assessment of external costs of nuclear accident would require a broader perspective, thus including a larger range of cost elements.

The main objectives of the study are as follows:


The final report is expected to be published by end of 2020.


“Methodologies for Assessing the Economic Consequences of Nuclear Reactor Accidents”, OECD Nuclear Energy Agency, Paris, 2000.

Background paper in document NEA/NDC(2012)22 (and references within it).


In the course of its activities, the Ad hoc Expert Group will collaborate with the International Atomic Energy Agency (IAEA), relevant research institutes and technical support organisations (TSOs) in OECD member countries.

The Ad hoc Expert Group will also collaborate with the other NEA Standing Technical Committees, notably the Committee on Radiological Protection and Public Health (CRPPH), the Nuclear Law Committee (NLC) and the Committee on the Safety of Nuclear Installations (CSNI).


The study will be led by the Committee for Technical and Economic Studies on Nuclear Energy Development and the Fuel Cycle (NDC) with the involvement of other divisions at the NEA in charge of radiological protection, legal and safety issues. An Expert Group will be established to conduct the study. The plan is to organise two workshops to cover, respectively, the methodological issues and the legal aspects.

At its 3rd meeting held in June 2014, the Expert Group discussed the title of the final publication. and agreed on the following title: “Estimation of potential losses due to nuclear accidents” [NEA/NDC(2014)12].

The Ad Hoc Expert Group will be disbanded upon completion and publication of the report.