© Vlastimil Šesták #142244892, source: stock.adobe.com 2019

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 is addressing both preparedness and rapid response to nuclear emergencies at the international level. It is achieving 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.

‘In particular, the capabilities of tools and methods have been 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,’ says project coordinator Isabelle Devol-Brown of the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) in France.

To complement the tools, the project has developed a database of nuclear accident scenarios and a common methodology. ‘The database of representative accidents and the common graduated response methodology, for a fast, organised and reliable prediction of accident development and atmospheric releases, can be implemented in any emergency centre,’ she says.

Real-world scenarios

The database contains uniform-format descriptions of over 100 emergency scenarios, including assessments of atmospheric releases – which are applicable to all four types of European nuclear power plant technology – and to spent fuel rods.

The project is improving already existing deterministic and probabilistic tools to rapidly assess atmospheric release models, and in response to nuclear emergency situations.

‘The project partners have also been working to produce or integrate atmospheric-release data in a standard format, IRIX, to link them with other initiatives focused on atmospheric transport, radiological consequence assessments and data assimilation,’ explains Devol-Brown.

Improved and extended tools developed by FASTNET are already operating in real-world situations. ‘The extended version of PERSAN, the deterministic rapid source term tool, is now being implemented in IRSN’s Technical Crisis Centre, while the extended version of the RASTEP probabilistic tool is used on a daily basis by the Swedish Radiation Safety Authority,’ Devol-Brown says.

Through numerous meetings and workshops, the project has enhanced interactions between partners, essential for developing a harmonised approach to implementing a robust and efficient common methodology capable of managing emergencies in European nuclear power plants and spent-fuel pools.

International scope

FASTNET involves a consortium of 20 partners from 18 countries, including the USA, Canada and the Russian Federation, as well as the International Atomic Energy Agency (IAEA) as a third party.

The project team organised a training session in May 2018 on the extended tools and method, as well as exercises to apply improved PERSAN and RASTEP tools and to implement and validate the common graduated methodology.

‘The first, in December 2018, targeted the best calculation of accidental atmospheric releases,’ says Devol-Brown. ‘The second, in February 2019, included how to manage and protect the population during nuclear accidents. Almost all project partners took part in the simulation games.’

When FASTNET ends, the team intends to transfer the database of nuclear accident scenarios to the IAEA where it will be maintained, extended to non-European nuclear technologies, and made available to emergency centres in all member countries.