Thorough preparation and rapid response are essential for dealing with emergency situations at nuclear power plants. However, these require different tools and methods. The EU-funded FASTNET project addressed both preparedness and rapid response to nuclear emergencies at the international level. It achieved this by combining the expertise of organisations in these two areas, and merging complementary approaches to take existing tools and methodology to the next level. “The capabilities of tools and method were extended to address a large set of accidents for the main types of operating or foreseen water-cooled nuclear power plants in Europe, including a generic concept for spent fuel pools,” notes project coordinator Isabelle Devol-Brown. Project partners also developed a database of nuclear accident scenarios, extended the capabilities of rapid source term tools and shared the extension of a common methodology. “The database of representative accidents, the rapid source term evaluation tools and the common graduated response methodology, for a fast, organised and reliable assessment of accident development and atmospheric releases, can be implemented in any emergency centre,” adds Devol-Brown.
The consortium developed a database that contains more than 100 descriptions of nuclear accident scenarios. This includes assessment of releases to the atmosphere, performed by partners using reference codes, that can be used for the four different European nuclear power plant technologies and a generic concept of spent fuel pool. The four technologies are pressurised water reactor, boiling water reactor, water-water energetic reactor and Canada deuterium uranium. “Project partners also integrated the data set of atmospheric releases in a standard format (international radiological information exchange – IRIX – standard) to link them with other initiatives focused on atmospheric transport, radiological consequence assessments and data assimilation,” explains Devol-Brown. The project coordinator has transferred the severe accident scenarios database to the International Atomic Energy Agency (IAEA). Furthermore, promising probabilistic approaches based on Bayesian belief networks were developed to complement deterministic methodology and tools used to diagnose accidental situations. The 3D3P method and the extended version of PERSAN, the deterministic emergency tool, are implemented in the Technical Crisis Center of the French Institute for Radiological Protection and Nuclear Safety. The extended version of RASTEP, the probabilistic emergency tool, is used on a daily basis by the Swedish Radiation Safety Authority and was developed in collaboration with Lloyd’s Register.
Past and upcoming activities
The consortium organised a training session in May 2018 on the extended tools and method, and offered exercises to apply improved PERSAN and RASTEP tools and to implement and validate the common graduated methodology. The first exercise, in December 2018, targeted the best calculation of accidental atmospheric releases. The second, in February 2019, included how to manage and protect the population during a nuclear accident. Now that the project has ended, the idea would be to organise a number of different activities to further enhance interactions between partners. These would include operational trainings for all types of nuclear power plants and spent fuel pools and a new series of benchmarking exercises leveraging spent fuel pool scenarios and source terms. It would also make available a new series of exercises targeting the protection of populations during nuclear disasters that will integrate a higher level of reality.
FASTNET, nuclear power plant, atmospheric releases, spent fuel pool, radiation, nuclear accident, rapid source term tools, methodology, PERSAN, RASTEP, IRIX