U. S. Nuclear Regulatory Commission

To the knowledge of the authors, these studies are the first hydraulic characterizations of a full length, highly prototypic 17 17 pressurized water reactor (PWR) fuel assembly in low Reynolds number flows. The advantages of full scale testing of prototypic components are twofold. First, the use of actual hardware and dimensionally accurate geometries eliminates any issues arising from scaling arguments. Second, many of the prototypic components contain intricacies by design that would not be reproduced by using simplified flow elements. While this approach yields results that are inherently specific to the fuel assembly under testing, the differences in commercial designs are considered minor, particularly when considering the hydraulics of the entire assembly.