Design and thermal-hydraulic transient analysis of helium-cooled solid target for ADS

The Accelerator Driven Sucritial Reactor System (ADS) is a kind of nuclear reactor which can burn minor actinide waste products produced from conventional reactors with inherent safety features. Because of the characteristics of a sub-critical reaction process, the fission chain reaction is maintained by additional neutrons generated in spallation target induced by proton beams. In this paper, a helium-cooled solid target was designed for a 10 MW helium-cooled prismatic-type experimental ADS. Tungsten is choosen as the spallation target material and is modeled into the honeycomb structure. High pressure helium, which flows in honeycomb holes, removes heat deposited by the proton beam in the target. FLUENT code was used to calculate the temperature distribution of target under steady condition, with UDF solving the flow of helium in channels. In order to analyze the transient characteristics of spallation target cooling system, a RELAP5-3DTarget coupling model for cooling system was established. A simplified method was developed to simulate the heat transfer in target. The method avoids fine grid and gets a solution quickly. The simulated results indicate that the peak temperature in the target is lower than the limiting value under operating state as well as three typical transient scenarios with protected system. (and others)