In this paper, the symmetric heat transfer performance of sodium-cooled fast
reactor fuel assemblies was analyzed and studied. The model is
analytically optimized based on sub-channel calculations. The deviations of
the numerical simulation results from the pre-existing experimental data
in the literature are within 10 %, with an average deviation of 2.5 %, which
tested the reliability of the model. The calculated results demonstrated
that the distribution of the axial power, temperature, and coolant of the
reactor core is approximately symmetric M-shape. The reactor core coolant
has a monotonic increase in axial distribution with the cladding temperature
and the temperature peaks all appear at the reactor core outlet. The individual fuel assemblies' internal temperature is relatively sensitive to
the axial power distribution, and there are troughs around the imports and
exports. The simulated results showed that the center temperature of the
hottest rod reactor core block reached 965.65 K. This pa- per provides a
better guide to understanding the overall heat transfer effect by optimizing
the heat transfer model.