Analysis of rapid-condensation transient using TRACE

A1-Dimensional TRACE model of the UMD-USNA Near One-dimensional Transient Experimental Apparatus (MANOTEA) facility was created and the output compared to facility data. The model over-estimated pressures and temperatures observed in the condenser during the experiment. In addition, the model always predicted that the condenser pipe would fill. In order to improve the model, a list of the phenomena was generated, and then mapped to TRACE parameters. This exercise was aimed at finding ways to capture the energy partition; and in doing so, prevent the condenser from filling. Over 250 TRACE cases were run, and the effective and physically justifiable parameters were incorporated into a 3-Dimensional Model. The 3-D Model incorporated non-condensable gases, providing a physical mechanism by which transient simulations could terminate smoothly. In addition, A VESSEL component was added to provide a rudimentary means to approximate the energy partition. The 3-D Model generally under-predicted trends observed in the experiments. Shortcomings in these initial models were discussed. In spite of the need for model improvement, the present work underscored the need to implement a droplet field in TRACE. This droplet field may improve simulations of MANOTEA transients by providing a better means to capture condensation phenomena occurring in the condenser vapor space. Published by Elsevier B.V.