In China, the demands for nuclear power have increased with increasing energy consumption. Thus, requirements in the treatment of spent fuel have also increased. As spent fuel is radioactive, cooling is required to prevent the spent fuel from reaching high temperatures. From the perspective of long-term development, dry storage casks have become a priority intermediate storage method in China. Before this storage method is put into application, the nuclear regulatory authority requires a thorough safety evaluation by experiments or analyses to ensure that it maintains its thermal safety function under normal, abnormal, and accident conditions. It is pointed out that experiments with the full-scale model are expensive and are typically very large. However, the safety of such structures may be examined through the use of a dimensionally scaled-down model. To ensure an accurate analysis of the scaled-down structures, the scaling of thermal-hydraulic behaviors from the prototype dry storage casks for spent fuel is required.
Firstly, a general scaling method of a conventional testing system is introduced in this paper. Secondly, the principle used to perform the scaling of a dry storage cask simulator is carefully explained. Then a Phenomena Identification and Ranking Table (PIRT) of thermal and flow behaviors involved in a dry storage cask are presented. After that, dimensionless criteria which are used to characterize thermal-hydraulic behaviors in the dry storage cask are derived. Finally, the distortion is numerically analyzed.