NEA Mandates and Structures

Working Group on Analysis and Management of Accidents (WGAMA)

Chair(s): Luis E. HERRANZ, Spain
Secretary:  Nils SANDBERG
Vice-Chair(s): Didier JACQUEMAIN, France
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
Union of the Electricity Industry (EURELECTRIC)
Date of creation:31 December 1999
End of mandate:31 December 2020

Mandate (Document reference):

Mandate (Document extract):

Extract from document NEA/CSNI/R(2017)17


The Working Group on the Analysis and Management of Accidents (WGAMA) shall be responsible for activities related to potential accidental situations in nuclear power plants, including the following technical areas: reactor coolant system thermal-hydraulics; design-basis accidents; pre-core melt conditions and progression of accidents and in-vessel phenomena; coolability of over-heated cores; ex-vessel corium interaction with coolant and structures; in-containment combustible gas generation, distribution and potential combustion; physical-chemical behaviour of radioactive species in the primary circuit and the containment; and source term. The activities will mainly focus on existing reactors, but will also have application for some advanced reactor designs. Priority setting will be based on established CSNI criteria and in particular on safety significance and risk and uncertainty considerations.

The WGAMA objective is to assess and, where necessary, strengthen the technical basis needed for the prevention, mitigation and management of potential accidents in nuclear power plants, and to facilitate international convergence on safety issues and accident management analyses and strategies.

In order to fulfil this objective, the Working Group shall:

The Working Group shall report to the Committee on the Safety of Nuclear Installations (CSNI) and assist that Committee with its work. The programme will be carried out by small task groups, each set up for performing a specific programme activity under the WGAMA supervision. The output of the Working Group will consist of state-of-the-art reports and other technical reports, workshops and conferences and related proceedings, benchmarking exercises and joint research proposals.

The Working Group will aim to provide answers as requested by the Committee on Nuclear Regulatory Activities (CNRA), the CSNI and member countries and will co-ordinate its work with other NEA bodies, notably with the Working Group on Risk Assessment (WGRISK) for priority setting and potential accident sequences, the Working Group on Operating Experience (WGOE) for emerging issues, the Working Group on Integrity and Ageing of Components and Structures (WGIAGE) for ageing and structure integrity evaluation, the Working Group on Fuel Safety (WGFS) for issues related to fuel safety, and the Working Group on Human and Organisational Factors (WGHOF) for human and organisational aspects of accident management. The WGAMA will also work in co-ordination with the Nuclear Science Committee (NSC) on scientific items such as advanced neutronic and thermal-hydraulic methods. Interaction with joint projects will be strengthened as recommended in the CSNI Operating Plan and Guidelines.