Study on the Behaviors of a Conceptual Passive Containment Cooling System

In this paper, a closed loop concept, which is composed of two heat exchangers with same scale, pipes, valves and one tank, has been developed as a passive containment cooling system for a large dry concrete containment. The system is designed to maintain the containment integrity by taking the heat drained into the containment following a severe accident, e.g. LOCA or MSLB. Under different conditions in containment, the system may operate in single phase mode or two phase mode. According to the design limitation of containment, the fixed temperature boundary condition is applied to the system analysis. We have developed the codes for the analysis of the system by ourselves. The operating behaviors of the system are studied numerically from startup to long term operation. In the light of the fact that the fraction of steam in the containment may be changing during the accident scenario, it is reasonable that the heat transfer coefficient will be different. Therefore, the sensitivity analysis of the heat transfer coefficient is also performed. Based on the results and corresponding analysis, it can be concluded that the system may be utilized to meet the design purpose for the containment integrity requirement.Copyright © 2013 by ASME