A review of critical heat flux prediction technique and its application in CANDU reactor

The CHF prediction method being used for CANDU reactor have been critically reviewed. The AECL's CHF prediction totally depends on the look-up table which has been developed from many CHF databank. These databanks include not only the water-cooled bundle-CHF data but also the freon-cooled bundle-CHF data. The CHF look-up tables have been developed by smoothing and interpolating (with some extrapolations) the experimental data to construct a practically useful CHF table. Therefore, the table look-up method has advantages of accuracy, consistency in a wide range of thermal-hydraulic parameters. It seems, however, that since the existing look-up table is constructed by many steps of modification of the original experimental data (e.g., the look-up table is constructed not only using the horizontal flow data but also the vertical flow data), one should be very careful when one try to generate a look-up table for other fuel geometries. In other words, a reliable look-up table can be constructed by performing experiments for new fuel geometry. Finally, it should be noted that the modifications to the original experimental data has simple form with many modification parameters for taking into account of different geometrical effects. This report presents the backbone and the validity of AECL CHF look-up table. (author). 22 refs., 2 tabs., 2 figs