Modelling and Validation of Catalytic Hydrogen Recombination in the 3d Cfd Code Gasflow Ii

During hypothetical core melt accidents steam and hydrogen can be released into the air filled containment of pressurized water reactors (PWR). Without counter measures flammable mixtures may form and cause combustion loads that could threaten the integrity of the containment. German PWR’s are now equipped with passive catalytic recombiners so called PARs (passive autocatalytic recombiners). They are arranged in boxes with arrays of plates coated with a platinum catalyst and are designed to prevent the accumulation of detonable conditions. Recombiner models have been implemented into the CFD code GASFLOW II to simulate such PAR mitigation in thermal hydraulic full containment calculations for various accident scenarios. After a brief description of these models this contribution will give the results from validation calculations of these models with a 3D experiment for plate recombiners (HDR test E11.8.1) and the thermal hydraulic analysis of larger scale experiments which investigated the performance of such box recombiners with steam/hydrogen release under realistic accident conditions. SAMPLE ABSTRACT PAGE