NEA Mandates and Structures


Working Group on Analysis and Management of Accidents (WGAMA)

Chair(s): Hideo NAKAMURA, Japan
Secretary:  Martina ADORNI
(martina.adorni@oecd-nea.org)
Vice-Chair(s): Ahmed BENTAIB, France
Member(s):All NEA member countries*
Russia (Suspended*)
*Russian Federation suspended pursuant to a decision of the OECD Council.
Full participant(s): European Commission
Under the NEA Statute
Participant(s): India
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 2026

Mandate (Document reference):

  • Summary Record of the 28th Meeting of the Committee on the Safety of Nuclear Installations (CSNI) [NEA/SEN/SIN(2001)1]
  • CSNI Operating Plan (2006-2009) [NEA/CSNI/R(2007)7]
  • Summary Record of the 40th Meeting of the CSNI [NEA/SEN/SIN(2007)1]
  • Summary Record of the 47th Meeting of the CSNI [NEA/SEN/SIN(2010)2]
  • CSNI Operating Plan (2011-2016) [NEA/CSNI/R(2011)2]
  • Summary Record of the 61st Meeting of the CSNI [NEA/SEN/SIN(2017)2]
  • Summary Record of the 68th Meeting of the CSNI [NEA/SEN/SIN(2020)3]
  • CSNI Operating Plan and Guidelines (2017-2022) [NEA/CSNI/R(2017)17/REV1]
  • Participant Status of India in the CSNI and its subsidiary bodies: 2018 Update of the NEA Participation Plan [NEA/NE(2018)8], Summary of Decisions taken at the 137th Session of the Steering Committee [NEA/SUM/DEC(2018)2] and official letter received from India on 31 October 2019 confirming its acceptance of Participant Status in the CSNI and its subsidiary bodies
  • 2022 Update of the NEA Global Relations Strategic Directions [NEA/NE(2022)18/REV1]
  • Summary of Decisions Taken at the 144th Session of the Steering Committee for Nuclear Energy [NEA/SUM/DEC(2022)2]
  • Summary Record of the 71st Meeting of the CSNI [NEA/SEN/SIN(2022)4]
  • Summary Record of the 73rd Meeting of the CSNI [NEA/SEN/SIN(2023)1]
  • Mandate of the Working Group on Analysis and Management of Accidents (WGAMA) [NEA/SEN/SIN/AMA(2023)2]

Mandate (Document extract):

Extract from document [NEA/SEN/SIN/AMA(2023)2]

Background

The Working Group on Analysis and Management of Accidents (WGAMA) created in 1999 by the Committee on the Safety of Nuclear Installations (CSNI) is to support CSNI in the following areas:

  • Increasing confidence in the validity and accuracy of thermal-hydraulic (T/H) and severe accident (SA) codes for the reactor safety assessment. To this end, the WGAMA organises international standard problem (ISP) exercises and benchmark studies based on relevant experimental data to strengthen the technical basis required for the prevention, mitigation, and management of reactor accidents.
  • analysis of past accidents to identify possible knowledge gaps and launch research activities that support the post-accident (post-Fukushima-Daiichi, for instance) decision-making process.
  • identification of sets of experiments for use in validating computer codes and on data preservation within NEA Joint Projects (JPs).

Scope

The WGAMA addresses NEA activities related to potential design-basis and beyond design-basis accidents in nuclear reactors and related technologies. The accident progression includes in-vessel and ex-vessel phenomena involving system thermal-hydraulics, core damage and relocation, release and transport of radioactive materials and their physical-chemical behaviour, combustible gas generation, distribution and combustion, and molten core-concrete/structure interactions. The WGAMA shall address the safety aspects of existing nuclear reactors and related technologies as well as emerging challenges of evolutionary and innovative reactor designs and nuclear technologies, including SMRs. Priority setting will be based on established criteria of the CSNI and in particular on safety significance, risk and uncertainty considerations.

Objectives

The WGAMA assesses and, where necessary, strengthens the technical basis needed for the prevention, mitigation and management of potential accidents in nuclear reactors and related technologies, and facilitates international convergence on safety issues, safety assessments and accident management (AM) measures and strategies.

In order to fulfil these objectives, the WGAMA will:

  • exchange relevant technical experience and information for resolving current or emerging safety issues;
  • promote the development of phenomena-based models and codes used for safety analysis, including the performance of benchmarking exercises;
  • assess the state of knowledge in areas relevant for accident analysis;
  • where needed, promote research activities aimed to improve such understanding, while supporting the maintenance of expertise and infrastructure in nuclear safety research.

Working methods

The WGAMA will report to the CSNI and assist the Committee with its work. The WGAMA will provide answers to questions from the CSNI and the Committee on Nuclear Regulatory Activities (CNRA).

The WGAMA will be led by a Chair, a Vice-Chair and a Bureau designated and acting according to the OECD guidelines. The WGAMA will also have a Group of Advisors, composed of senior international experts, that can be appointed and called by the chairpersons to provide advice on specific issues.

The programme of the WGAMA will be carried out by small task groups (TGs), each set up for performing a specific programme activity under the WGAMA’s supervision. All activities have a co-ordinator or a leader who is responsible for work performance.

Membership

The WGAMA is comprised of NEA member country representatives identified as senior experts in nuclear safety, typically from nuclear regulatory authorities, technical support organisations (TSOs), industry or academia.

Delegates from non-member partner countries (participants or invitees) may also attend WGAMA meetings (according to the Global Relations Strategic Directions of the Steering Committee for Nuclear Energy).

Interactions

The WGAMA co-ordinates 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 New Technologies (WGNT) for regulatory concerns on new technologies, 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 which includes accident-tolerant fuel (ATF) subjects, and the Working Group on Human and Organizational Factors (WGHOF) for human and organisational aspects of AM. Co-operation with other CSNI and CNRA WGs should aim at activities based on defined/agreed priorities in both groups.

The WGAMA also works in co-ordination with the Expert Group on Reactor Core Thermal-hydraulics and Mechanics (EGTHM) of the Nuclear Science Committee (NSC) on scientific items related to advanced thermal-hydraulic methods, including coupling techniques with other codes (e.g., neutronics, fuel performance, CFD).

The NEA provides a framework for establishing joint safety research projects, and the CSNI expects that the WGAMA will promote technical exchanges by creating opportunities with relevant projects, and provide technical support as appropriate.

The WGAMA engages with the following international bodies specialised in similar sets of activities to ensure complementarity and increase synergy: the International Atomic Energy Agency (IAEA), the European Commission, other organizations where a memorandum of understanding (MOU) is established with the NEA, such as the American Nuclear Society (ANS), the CANDU Owners Group (COG), the Central Research Institute of Electric Power Industry (CRIEPI), the Electric Power Research Institute (EPRI), and other international organisations.

Deliverables

The WGAMA will produce state-of-the-art reports and other technical reports, workshops and conferences with related reports and proceedings, benchmarking exercises and joint research proposals. One or more (internal) reports are usually issued for each of the activities. Final reports are issued as CSNI reports.

The activity derived from tentative and long-term TGs are mostly published as technical reports, which include phenomena identification ranking table (PIRT), CSNI Code Validation Matrix (CCVM)), a technical opinion paper (TOP), a summary report and/or proceedings of WS, and a report of international standard problem (ISP) and benchmark activities, providing status and recommendations.