International Nuclear Emergency Exercises (INEX): 1993-2001

    The INEX series of international nuclear emergency exercises, organized under the OECD Nuclear Energy Agency's (NEA) Working Party on Nuclear Emergency Matters (WPNEM), have proven successful in testing, investigating and improving national and international response arrangements for nuclear accidents and radiological emergencies. Previous INEX exercises focused largely upon national and international aspects of early phase management of nuclear power plants emergencies. The NEA's work on International Nuclear Emergency Exercises began with the INEX-1 Exercise in June 1993.

    INEX 2000

    In the tradition of the NEA-initiated INEX exercises, an extensive international nuclear emergency exercise, INEX 2000/JINEX 1, was carried out on 22-23 May 2001, based on a French national exercise at the Gravelines nuclear power plant in the north of France, near the Belgian border. The Gravelines site contains six pressurised water reactors, each providing 910 MWe of electrical power. The exercise involved a simulated incident in the fictitious Gravelines Unit 11 including a release of radioactivity to the environment.

    Based on actual weather conditions at the time of the exercise, the French authorities would have evacuated 8000 people and recommended the intake of stable iodine to protect the public living in the vicinity of the power plant. The simulated accident was rated four on the international nuclear event scale (INES). The exercise allowed participants to test existing national and international procedures and arrangements for responding to a nuclear emergency, co-ordinate the release of information, and assess the effectiveness of advisory and decision-making mechanisms. In addition, web-based information exchange mechanisms were tested following the NEA initiative to promote the implementation and testing of modern monitoring and data management strategies for nuclear emergencies. The need for more modern monitoring strategies was identified in the report Monitoring and Data Management Strategies for Nuclear Emergencies. A total of 54 countries and five international organisations participated in the exercise.

    INEX 2000 for the first time addressed questions of civil liability following a nuclear emergency. An International third party liability workshop addressed these issues using the scenario from the scientific/technical exercise. The workshop took place on 26-28 November 2001 in Paris and aimed to test the mechanisms by which potential victims of this simulated accident, both in France and in the affected neighbouring countries, would be compensated. One of the principal objectives was to examine the manner in which the Paris Convention on Third Party Liability in the Field of Nuclear Energy and the Brussels Supplementary Convention would be applied.

    The INEX 2000 exercise objectives, from the NEA perspective, were to test the features of Monitoring and Data Management Strategies for Nuclear Emergencies, including such areas as:

    • evaluating the effectiveness of the developed data matrix;

    • examining t he effectiveness of proposed communication strategies employing new technologies;

    • testing the co-ordination of information provided to the media between the various participants;

    • testing the mechanisms for the implementation of the Convention on Third-Party Liability; and

    • identifying how participants incorporated the lessons of INEX 2.

    The exercise led to short-term follow-up activities. These included evaluating the practical implications of further optimisation of the communication strategy developed.

    INEX 2 exercise series

    Based on the experience of INEX 1 and its associated workshops, it was agreed that a second, more realistic exercise should be developed and sponsored by the NEA. INEX 2 used as its basis a national-level emergency exercise at an existing power plant. In order o investigate the various international aspects of accident planning, preparedness and management, three exercise objectives were added to the national-level exercise:

    • Decision-making based on limited information and uncertain plant conditions;
    • Use of real time communications with the actual equipment and procedures; and
    • Public information and interaction with media.

    Other countries were invited to participate using their actual hardware, software, procedures and facilities as if it were an actual emergency. Countries then received and collected accident information, performed accident situation analyses and made decisions in real time.

    To allow several different countries in different geographical areas to "host" an INEX 2 exercise, it was agreed to hold four regional exercises roughly equally spaced in time between mid-1996 and early 1999. For each of these regional exercises, an "accident host" country proposed to use a previously planned and scheduled national-level command-post exercise as a platform for the INEX 2 objectives. Other participating countries activated their own emergency command posts and used existing bilateral and multilateral notification and communication agreements, as well as such agreements with international organisations (IAEA and EC), to receive and transmit information. Only the information gathered through these normal channels were used as the basis of decision-making (countermeasures, public information, data management, etc.). Four exercises were held:



    Nuclear Power Plant

    Swiss INEX 2

    November 1996

    Leibstadt (BWR)

    Finnish INEX-2

    April 1997

    Loviisa (PWR)

    Hungarian INEX-2

    November 1998

    Paks (PWR)

    Canadian INEX-2

    April 1999

    Darlington (CANDU)

    Early on during the Swiss and Finnish INEX 2 exercises it became clear that in an emergency situation more information than is currently available would be necessary to ensure that decisions and public information were based on appropriate knowledge. The existing procedural and technological means for information and data transmission were shown to be in need of improvement and modernisation.

    To address these concerns, three working groups were established in order to prepare a coherent strategy to:

    • Better identify key emergency data;
    • Improve emergency communication and information management; and
    • Improve emergency monitoring strategies.

    The results of this work are summarised in the report Monitoring and Data Management Strategies for Nuclear Emergencies, The objective of this new strategy is to assist the decision maker by improving the selection of the data which is being transmitted, the transmission and reception of data and information using modern communication methods, (e.g. secure internet technologies), and by defining emergency monitoring and modelling needs.

    Many NEA Member countries, the European Commission and the International Agency Energy Agency are implementing this strategy. Other countries and international organisations (the World Health Organization, World Meteorological Organization, and the United Nations Office for the Coordination of Humanitarian Affairs) are considering how best to adapt the strategy to their roles and needs.

    INEX 1

    The NEA's work on International Nuclear Emergency Exercises began with the INEX 1 Exercise in June 1993. The objective of this exercise was to identify important policy issues and areas where transboundary communication and co-ordination could be improved. An important issue here was the intervention levels which had been adopted by various countries, and how the implementation of countermeasures was co-ordinated, particularly in border regions.

    An assessment of INEX 1 exercise results revealed three areas for further work. To address these issues, three workshops were held, between 1994 and 1996:

    • The implementation of short-term countermeasures after a nuclear accident;
    • Agricultural aspects of nuclear and/or radiological emergency situations;
    • Nuclear emergency data management.

    Based on the experience from INEX 1 and from the three follow-up workshops, a more realistic international nuclear exercise was launched. INEX 2 was planned as a series of regional, command-post exercises with the voluntary and simultaneous real-time participation of many countries. The objectives of this exercise series focused on the real time exchange of information, public information and decision making based on limited information and uncertain plant conditions.

    Last reviewed: 26 August 2016