Code-experiment comparison on wall condensation tests in the presence of non-condensable gases—Numerical calculations for containment studies

During the course of a severe Pressurized Water Reactor accident, pressurization of the containment occurs and hydrogen can be produced by the reactor core oxidation and distributed in the containment according to convection flows and wall condensation. Filmwise wall condensation in the presence of non-condensable gases is a subject of many interests and extensive studies have been performed in the past. Some empirical correlations have demonstrated their limit for extrapolation under different thermal-hydraulic conditions and at different geometries/scales. The French Institute for Radiological Protection and Nuclear Safety (IRSN) has developed a numerical tool and an experimental facility in order to investigate free convection flows in the presence of condensation. The objective of this paper is to present numerical results obtained on different wall condensation tests in 7 m3 volume vessel (TOSQAN facility), and to compare them with the experimental ones. Over eight tests are considered here, and code-experiment comparison is performed on many different locations, giving an extensive insight of the code assessment for air–steam mixture flows involving wall condensation in the presence of non-condensable gases.

► Steam condensation on walls has been investigated in the TOSQAN vessel.
► Experiments on 7 different tests have been performed.
► Different steam injections and wall temperatures are used.
► Simulations are performed in 2D using the TONUS code.
► Code-experiments comparisons at many different locations show a good agreement.