Program development and study on supercritical CO2-cooled reactor sub-channel thermal hydraulic.

• A more detailed sub channel program SACOS-SCO2 is developed. • Some typical accidents in the reactor are analyzed to ensure the safety of the reactor. • The calculation results of the program SACOS-SCO2 provide a reference for reactor core design Most of the researches on supercritical CO 2 -cooled reactors focus on the design of core performance parameters world widely, but few on the detailed thermal hydraulic analysis. To supplement the lack of research in this area, in this study, the supercritical CO 2 -cooled reactor designed by the Nuclear Institute of China is taken as the resect. A complete solution method based on the thermal hydraulic model is established. And the sub-channel code SACOS-SCO 2 is developed. The results of SACOS-SCO2 are compared with experimental results of SCUOL and code results of KAIST, and the good agreement fully illustrates the calculation ability of SACOS-SCO 2. Based on the above models and codes, the thermal hydraulic characteristics of supercritical CO 2 -cooled reactor designed by the Nuclear Institute of China are analyzed under the conditions of reactivity introduction accident and the loss of flow accident. Through theoretical modeling and self-developed codes, the sub-channel thermal hydraulic characteristics of supercritical CO 2 -cooled reactor are studied, which can provide a powerful reference for the design and safety analysis of supercritical CO 2 -cooled reactor. [ABSTRACT FROM AUTHOR]