On October 8th, 2025, The Sustainable Nuclear Energy Technology Platform (SNETP) hosted its 8th SNETP Project Portfolio seminar. On this occasion, the webinar brought together two projects stemming from the Technical Area 2 (Severe Accidents, SA) of the NUGENIA pillar and funded by EURATOM: SOCRATES and AMHYCO.  

The intention was to show two key stages in the evolution of a Severe Accidents project: the first step, when the main project pillars are being settled (SOCRATES); and the project end, when the research results are translated into lessons learned to make nuclear reactors safer through an enhancement of SA management guidance (AMHYCO). In addition to these projects, there are currently three other projects running in NUGENIA/TA2: SEAKNOT, ASSASS and SASPAM-SA. 

Assessment of Liquid Source Term for Accidental Post Management Phase (SOCRATES) 

Teemu Kärkelä (VTT, Finland), coordinator of SOCRATES, walked us through the motivation and main pillars of the project.  By emphasizing the significance of liquid source term in the Fukushima accident context, he underscored the relevance of properly managing liquid source term and assessing the potential offsite consequences. Finally, he described the work ongoing in terms of experimental matrices that are being built to search for leaching mechanisms and late fission product chemistry in aqueous phases. The resulting databases will be the seed for new models and correlations that will strengthen, in the end, the analytical capability to better manage and assess liquid source term in case of a SA. 

Towards an enhanced accident management of the hydrogen/co combustion risk (AMHYCO) 

Gonzalo Jiménez (UPM, Spain), coordinator of AMHYCO, introduced the macroscopic numbers of the project and quickly focused on what's been the most impacting findings on combustible gas behavior during a SA in a pressure water reactor (PWR), particularly once the reactor pressure vessel fails. Based on the knowledge state at the onset of the project, a numerical database of accident sequences simulations and generic containment models for three different PWR containments, AMHYCO obtained new data on recombination and combustion of hydrogen (H2) and carbon monoxide (CO). This enabled the development of new correlations for both phenomena and proposed new metrics to characterize combustion risk of both gases. Likewise, a reliable cross-comparison of different methodologies showed their consistency and the potential of advanced modelling to provide local information during a SA that might be critical in the management of accidents. As for practical applications, AMHYCO proved the effectiveness of autocatalytic recombiners to remove combustible gases and how their performance is affected by other engineering safety features available during accidents. 

Looking Ahead 

Both projects highlighted their commitment to education and training and the means displayed to support young researchers careers.   

The next webinar will take place the 28 November 2025, and will focus on two other Euratom-funded projects GEMINI 4.0 and PIANOFORTE. Register here.