Theoretical modelling and system response of a passive containment cooling system

A passive containment cooling system is proposed to be incorporated in advanced water-cooled reactors being designed in India. The system provides long term cooling for the reactor containment following a loss of coolant accident. The passive containment cooling system removes energy by steam condensation without any electric power or operator's action. A computer code TAPCON to analyse performance and the behaviour of the system has been developed. The models for inter compartment flow and condensation of steam with and without the non-condensable gas in the vertical tubes have been incorporated in the computer code. The model for the condensation of steam in presence of non-condensable gas is based on experimental studies performed close to atmospheric pressure. The analysis has been carried out for constant steam input rate and varying steam input rate simulating the decay heat. The theoretical results are compared with the experimental results for both the cases. (orig.)