Experimental Study of Natural Convection Behavior of a Passive Air-Cooled Containment System Relevant to Advanced Nuclear Reactor Comparisons of Heat Transfer Behavior With and Without Chimney

Safety systems, like the passive containment air-cooling system, are used to remove heat from a containment during accident conditions in advanced nuclear reactors, including small modular reactors having a steel containment. For the effective performance of the passive containment air cooling system with and without a chimney, it is highly important to understand the natural convection air flow around the containment. The experimental investigation of passive containment air cooling of an experimental test setup with and without a chimney, with a geometry very similar to that of an actual reactor, is presented in this paper. Comparisons between the air-side transient natural convection characteristics with and without a chimney were studied in detail based on the temperature measurement. The effect of a chimney was found to have an adverse effect on natural convection behavior due to possible air recirculation zones and restrictions to air flow due to its present shape.