Preliminary safety analysis on loss of flow accidents and external source transients for LBE cooled ADSR core

Highlights: •The primary side of a 800 MW accelerator-driven system is designed. •The point kinetics model of RELAP5/MOD3.3 code is modified to meet the requirement of ADS simulation. •The property of lead-bismuth is implemented. •The loss of flow accidents and reactivity insertion accidents are analyzed. -- Abstract: In this paper, preliminary safety studies on the 800 MWth accelerator-driven system (ADS) proposed by Xi'an Jiaotong university are presented. The system is a pool type facility coupling a proton accelerator with current in the range of 17–23 mA and a sub-critical core by means of a spallation target. The RELAP5/MOD3.3 code is selected as a base tool. In order to simulate the system, the point kinetics model is modified and the property of lead-bismuth is implemented to meet the requirement of ADS analysis. This paper focuses on the assessment of its response to the loss of flow events. The first part is originated from the failure of the pump and the second part derives from the significant flow blockage at a fuel assembly inlet. The reactivity insertion accidents are caused by the change of the proton beam current. The results show that the safety and criteria are satisfied and the system is tolerant to the loss of flow accidents and proton beam doubled accident and is sensitive to the external neutron changing.