Characterization of the plutonium dioxide airborne release fraction during glove box fires in nuclear fuel fabrication and reprocessing plants: presentation of the figaro research project and its first outcomes
Résumé
Accidental fires in nuclear fuel fabrication and reprocessing plants can cause the rupture of the glove box (GB) containment with a risk of dispersion of plutonium dioxide (PuO2) within the facility. Fire safety analyses need an assessment of the resulting radiological consequences to strengthen the appropriate prevention and protection measures in these plants. To this end, the French institute for radiological protection and nuclear safety (IRSN), in partnership with the Japanese nuclear regulation authority (NRA), has carried out since 2019 a research project that aims at assessing the airborne release fraction (ARF) of PuO2 involved in GB fires. This project, named FIGARO (Fires Involving Glove boxes with Aerosol Release Occurrences) follows a phased approach, starting with small and medium-scale analytical tests to study separately the various mechanisms involved in the GB fires and the PuO2 airborne release and ending with large-scale GB fire tests to transpose and validate the analytical works for realistic assessments of the ARF of PuO2 in confined conditions. This project also includes the development of a GB fire model in the IRSN SYLVIA and CALIF3S-ISIS softwares and its validation. In addition to presenting the FIGARO project, this paper provides its first outcomes.