Measurement of core flow distribution in a research reactor using plate-type fuel assembly

•The core flow distribution of research reactors was investigated to determine the flow uniformity in the reactor core.•A specially instrumented dummy fuel assembly was developed to measure the flow rate at each fuel assembly location.•The measurement results showed that the primary coolant flow in the reactor core was distributed evenly with a small deviation of −2.9%~+2.3%, even though the CAR position changed.