Effects of filtered containment venting system operating strategies on the cesium releases during severe accidents

Abstract

When a severe accident occurs, steam, hydrogen, non-condensable gas, and radioactive materials are generated and released from reactor coolant system CS) to containment atmosphere resulting in increase of containment pressure. The generation of steam and non-condensable gas could affect containment integrity which is a final barrier of radioactivity release. To prevent over-pressurization of containment and to reduce the amount of radionuclides release to the environment, the concept of Filtered Containment Venting System (FCVS) is adopted. However, the operation of FCVS is needed to be careful because it emits radioactive materials into the atmosphere which can affect to the public and environment ultimately. Especially, the Cesium (Cs) could have a major impact on human health and ground contamination. In addition, the effects of FCVS differs depending on accident scenarios and venting strategies. Therefore, in this paper, the effects of FCVS operating strategies on the Cesium during severe accidents are analyzed. Consequently, this study suggests the optimum venting strategies of FCVS in order to minimize the amount of Cs released to the environment. © 2018 American Nuclear Society. All rights reserved.