The design and thermohydraulics study of the HTR-10 High Temperature Helium Experimental Loop

•The transportation and deposition behavior of solid fission products are studied.•The designed device can assure a full-length temperature control evenly.•The designed device can simulate the real physical environment.•The graphite dust particle trajectories in the device are simulated.•The temperature distribution and fluid motion in the device are simulated.

A High Temperature Helium Experimental Loop (HTHEL) for the purpose of studying the transportation and deposition behavior of solid fission products in high-temperature helium coming from the steam generator (SG) in the 10 MW High Temperature Gas-cooled Test Reactor (HTR-10) is studied and designed. Through the optimal design based on thermohydraulics analysis, the three-sleeve structure of deposition sampling device (DSD) could realize full-length temperature control evenly and simulate the physical environment of the heat transfer tube of SG in the HTR-10 in the sense of thermohydraulics, which could be used to study the original source term in the primary circuit. The simulation of the graphite dust particle trajectories in the DSD are shown and it is elucidated that DSD could also be used to study the behavior of graphite dust in the high temperature helium in the SG of HTR, which will provide deeper understanding for the analysis of source terms of HTR-10.