SENSITIVITY ANALYSIS OF POWER RELATED PARAMETERS IN A REACTIVITY-INITIATED ACCIDENT OF A MOLTEN SALT REACTOR

Molten salt reactor (MSR) is one of the promising candidate Generation IV reactor technologies for future consideration. The rapid power rise during the accident is usually a critically important threat for the safety of a reactor. In a MSR, the increasing of reactor structural temperature caused by power rise may damage the integrity of reactor pressure boundary. During the accident scenario simulation of a MSR, the trend of reactor power really depends on the initial power, power peaking factors, and fuel salt and moderator temperature reactivity coefficients. This work aims to identify how these parameters influence the consequences of the accident for a MSR. In this study, a reactivity-initiated accident (RIA) is considered as the initiating event, which is caused by the withdrawal of control rod during power operating. This accident will lead to a rapid increase of reactor power and core temperature. A local sensitivity analysis was utilized to analyze the power related parameters. And a wide variety of values were selected for each parameter as the assuming initial conditions of the analysis. Multiple thermal-hydraulic simulation runs through a modified RELAP5 code were performed to acquire the accident analysis results for sensitivity analysis. According to the results of sensitivity analysis: power related parameters have a low impact on the consequence of the reactivity-initiated accident under power condition of the molten salt reactor. And the consequence of the accident is more sensitive to the changes in power peaking factors than the other parameters.