Development of External Fin Structure for Transport and Storage Cask and Verification of Its Heat Dissipation Performance

To improve heat dissipation performance for the transport and storage cask, applicability of short and compact external fins (micro fins) was investigated. The fins have an effect on increase of surface area, have advantages in designing cask with geometric control, and are available for cask both in vertical position and horizontal position. Heat transfer tests with fin elements were conducted to verify their heat dissipation performance after estimating optimal shape with the maximum heat dissipation performance of micro fins (the maximum heat transfer on the surface) with CFD analyses. The results showed that increase of heat transfer was not proportional to multiplication factor of area in these fin structure. In addition, a cask equipped with micro fins was designed, and thermal analyses during transport and storage were conducted. The analyses results proved that the cask equipped with the micro fins satisfies the prescribed performance during both transport and storage conditions.