Correlation Between the Critical Heat Flux and the Fractal Surface Roughness of Zirconium Alloy Tubes

摘要

In CANDU~R fuel channels, Zircaloy calandria tubes isolate the hot pressure tubes from the cool heavy water maderator. The heavy-water moderator provides a backup heat sink during some postulated loss-of-coolant accidents. The decay heat from the fuel is transferred to the moderator to ensure fuel channel integrity during emergencies. Moderator temperature requirements are specified to ensure that the transfer of decay Heat does not exceed the critical heat flux(CHF)on the outside surface of calandria Tube.