Experimental study of the flow characteristics in an SFR type 61-pin rod bundle using iso-kinetic sampling method

Hydrodynamic experiments were performed to characterize pressure drop and flow distribution in the subchannels of KAERI's fuel bundle configuration. A 61-pin wire wrapped rod bundle was chosen as a test assembly considering the hydrodynamic similarity of the prototype reactor. The rod diameter, rod length and rod pitch were 8.0 mm, 1500 mm and 1.14, respectively. Three instrument pins were specially fabricated to measure the pressure drop. Flow measurements for all subchannels including interior, edge and corner subchannels, were performed under iso-kinetic conditions. The nominal operating flow conditions of the test assembly were 15.02 kg/s at 60 °C with water, which is equivalent to Re ∼ 60,750. Conventional hydrodynamic correlations were assessed using the measured pressure drop and subchannel flow rate data. The experimental data of the pressure drop and flow distribution in the subchannels can be utilized to validate hydrodynamic models and subchannel analysis codes.