Accident of lead-bismuth subcritical reactor XADS

BackgroundIn accelerator driven sub-critical system (ADS), the high-energy proton beam produced by accelerator is used to strike the target nucleus, and generate spallation neutrons as external neutrons to drive and maintain its operation. The power level and the safety of ADS are susceptible to the instability of proton beam, such as beam overpower (BOP) which is treated as the typical transient accident for ADS system. In ADS core, the sudden increases of power and temperature will be caused by BOP accident, which may exceed the safety limits of materials, threatening ADS safety.PurposeThis study aims to investigate the transient safety characteristics of the eXperimental accelerator driven system (XADS) under BOP accident.MethodsThe multi-physics coupling code MPC-LBE, in which the fuel pin heat conduction (HC) model and the point reactor kinetics (PK) model were coupled with self-developed computational fluid dynamics (CFD) code, was employed to simulate BOP accident of XADS. Firstly, the MPC-LBE simulati