Progress in modeling in-containment source term with ASTEC-Na

The ASTEC-Na code is being developed to simulate any sort of postulated accidents in Na-cooled fast reactors, particularly severe accidents. A significant progress has been made in the development of source term models, their implementation in the code and the specific validation of the specific code module, hereafter named CPA∗, under the auspices of the JASMIN project. In this paper the fundamentals of models for Na pool fire thermal-hydraulics and particle generation and chemical ageing of airborne particulates are described. Based mostly on data gathered from the open literature, CPA∗ performance under conditions anticipated during Na pool fires has been assessed against AB1, AB2, F2 and EMIS10 experiments. Thermal-hydraulic estimates have shown acceptable generic trends with noticeable quantitative deviations, despite the highly parametrized models used. A similar statement concerning aerosol behavior following measurements tendency is also applicable. As for chemical ageing, the comparisons set indicate that further work is still necessary. Therefore, even though some significant progress has been achieved, it is unquestionable that further work needs to be done in the three areas addressed. Finally, it should be highlighted that one of the main outcomes of this work is the need of obtaining qualified data for models and codes validation, so that a thorough and sound model assessment and code validation can be conducted. © 2017 Elsevier Ltd