Abstract
A high efficient and reliable residual heat removal system (RHRS), which is of great importance in the development of Lead-Bismuth Cooled Fast Reactor (LBFR), was conceptually designed in present study. Based on the design of the RHRS and LBFR, the RELAP5 4.0 code is used to model the system, and then the numerical calculation of steady and transient state was carried out to obtain the important thermal-hydraulic characteristic parameters. Meanwhile, the variations of the parameters were obtained during the transient process, such as the fuel cladding temperature and the natural circulation mass flow rate. The results show that the mass flow rate of the core finally stabilizes at 3.9 kg/s, which is about 1.35% of the rated flow. The peak cladding temperature is less than 750.3 K within 72 h during the whole process, which is far below the temperature safety limit. Therefore, it can be considered that the RHRS can successfully remove the core decay heat of LBFR. This research lays a solid technical foundation for the conceptual design of the RHRS.
