Simulation and Experimental Verification of Boron Diffusion and Mixing in T-Tube Flow

10B has a high neutron absorption cross section, so boric acid is generally used as a neutron absorber for reactor control. During an emergency of a nuclear power system, boric acid water is injected into the reactor core by safety injection system to shut down the reactor. Boron concentration has an important impact on the operation safety of the power plant. The mixing process of boric acid and water is influenced by diffusion, convection and turbulence. A new laser-induced fluorescence method is proposed, which can accurately and quickly measure the concentration field of boric acid. This paper introduces the measurement method and the experimental study of boric acid diffusion in T-tube, and compares it with the measurement of wire mesh sensor. In addition, the CFD method is used to calculate the experimental conditions. The results obtained by the three methods were compared with each other, and the diffusion law and research of boric acid are obtained. This study can provide a certain basis for the follow-up study of boron diffusion.