In order to design a scaled-down moderator facility for simulating the CANDU-6 moderator circulation phenomena during steady state operating and accident conditions, an experimental study has been performed to investigate several problems at a 1/40 scaled-down moderator tank model. With a transparent moderator tank model, a flow field was preliminarily measured with a Particle Image Velocimetry(PIV) flow visualization technique under an isothermal state and Planar Laser Induced Fluorescence(PLIF) technique was also to evaluate the feasibility of temperature field measurement in the range of 20-40℃ with an one-color method.