AMHYCO Project - Advances in H2/CO Combustion, Recombination and Containment Modelling

During a severe accident in a nuclear power plant, one of the potential threats to the containment is the occurrence of energetic combustion events. In modern plants, Severe Accident Management Guidelines (SAMG) as well as dedicated mitigation hardware are in place to minimize/mitigate this combustion risk and, thus, avoid the release of radioactive material into the environment. Advancements in SAMGs are in the focus of AMHYCO, an EU-funded Horizon 2020 project officially launched on October 1st, 2020. The project consortium consists of 12 organizations (from six European countries and one from Canada) and is coordinated by the Universidad Politécnica de Madrid (UPM). The progress made in the first two years of the AMHYCO project is here presented. A comprehensive bibliographic review has been conducted, providing a common foundation to build the knowledge gained during the project. After an extensive set of accident transients simulated both for phases occurring inside and outside the reactor pressure vessel, a set of challenging sequences from the combustion risk perspective for different power plant types were identified. At the same time, three generic containment models for the three considered reactor designs have been created to provide the full containment analysis simulations with lumped parameter models, 3-dimensional containment codes and CFD codes. In order to further consolidate the model base, combustion experiments and performance tests on passive auto-catalytic recombiners under explosion prone H2/CO atmospheres were performed at CNRS (France) and FZJ (Germany). Finally, it is worth saying that the experimental data and engineering models generated from the AMHYCO project are useful for other industries outside the nuclear one.