Limiting the consequences of a severe reactor accident: the results of the European PASSAM project

The European project Passive and Active Systems on Severe Accident Source Term Mitigation (PASSAM) was launched in 2013 with a view to improving retention of radioactive releases after a core-damage accident in a light water reactor. In four years, the project has provided useful information on the filtering of these releases.

In the aftermath of the Fukushima accident, the purpose of the PASSAM project (carried out between 2013 and 2016 with eight other European partners(1) under IRSN's leadership) was to improve the systems for filtering radioactive releases in nuclear reactors and study innovative systems, focusing on trapping the iodine compounds that pose a major health risk over the short term. A number of existing devices such as pool scrubbers, sand filters and metal prefilters, and innovative system such as high-pressure sprayers, electrostatic precipitators, advanced zeolites, acoustic agglomeration systems, combined wet/dry filtration systems, have been studied experimentally. This helped to improve the existing calculation models, and to establish new ones. These models are implemented in severe accident calculation software such as ASTEC, which is developed by IRSN.

In four years, the PASSAM project made it possible to establish an experimental data base for each filtration system. These should help to improve the reliability of existing systems in operating nuclear power plants or be used for the design of new systems.

The project ended in late February 2017 with a seminar in Paris, attended by some one hundred participants. The results of PASSAM are covered in a final report that is available on IRSN's website.

Learn more at:

(1) Areva GmbH (Germany), CIEMAT (Spain), CSIC (Spain), EDF (France), PSI (Switzerland), RSE (Italy), Université de Lorraine (France), VTT (Finland).


Thierry Albiol, IRSN