Evaluation of an aerodynamic barrier approach to limit the dispersion of fission products in the event of containment failure

Abstract

A new accident mitigation approach based on the concept of aerodynamic barriers was examined for limiting the spread of radioactive material in the event of the containment failure at a nuclear power plant. This approach is based on utilizing airflow movements to confine and capture the radioactive material released outside the containment. Four representative configurations based on the number of aerodynamic towers, the distance, the angle of discharge and speed, and the suction systems were considered to investigate the effectiveness of the proposed approach under the postulated conditions of winds and fission products release. Computational fluid dynamic (CFD) modeling was used to model the transport of released fission products and to determine their capture efficiency under the influence of the proposed system. The results showed using six towers for generating airflows was capable of providing the necessary protection and confinement. The tower distance from the containment building was found to play a key role in confining the released materials. The inward oriented towers were shown to generate relatively stronger aerodynamic barrier flow around the containment building that improve the confinement and capture performance. Increase in tower discharge speed in general improved the barrier performance. While preliminary in nature, this study indicates the feasibility of accident mitigation by using aerodynamic barriers. Future studies are needed to perform detailed parametric/sensitivity studies on the key parameters to enable the implementation of the proposed system through automated operation.