Thermal-hydraulic modeling and transient analysis of helium-cooled tungsten target coupled with ADS core

In the design scheme, the tungsten spallation target was modeled into the honeycomb structure. The thermal-hydraulic model of the target coupling with core was built, in which the solid domain was simulated with three-dimensional heat conduction model and the fluid domain was simulated with one-dimensional quasi-static model. The target was modeled with fine meshes. The core was modeled roughly as the boundary condition of the target. In order to analyze the transient characteristics of the target with cooling system, a RELAP5-TRCAP coupling model for cooling system was established, in which the decay heat of the target and core was considered. The simulated results indicate that the peak temperature in the target is lower than the limiting value under the rated operation state and during the Loss of Flow Accident (LOFA) transient with actuation of the safety system.