Preliminary study on FROBA-SCO2 with transient models and its application for Reactivity Initiated Accident and loss of flow accident

Abstract

As a coolant enabling the reactor with a high efficiency and low volume, the supercritical CO2 has becoming a hot topic nowadays. However, the fuel rod behaviors under accidents are not studied thoroughly, especially the interaction between the coolant and the cladding. With the previous study of fuel rod behaviors analysis of supercritical CO2 cooled nuclear reactor under steady state operation, transient state models are implemented and the upgraded code can be used to predict the fuel rod behaviors under RIA and LOFA. After the comparation of the calculation results with SACOS-SCO2, the tendency and numerical value are close, so the accuracy is warranted. The upgraded FROBA-SCO2 is used to predict the fuel rod behaviors under RIA and LOFA conditions and the results indicate that the maximum temperature of cladding and fuel is within safety limits.