Development of thermal-hydraulic analysis code for spent fuel assembly of sodium cooled fast reactor

In order to analyze the thermal-hydraulic characteristics for spent fuel assembly of sodium cooled fast reactor, thermal-hydraulic code SPATANS for spent fuel assembly of sodium cooled fast reactor was independently developed. SPATANS code was based on sub-channel analysis method, and flow heat exchange and mixing correlations fitted for lower flow were used in the code. Computation was performed for bundle region of spent fuel assembly, and thermal parameters such as temperatures and pressures for various sub-channels at different heights of assembly were got. Computation results were compared with those of three-dimensional computational fluid dynamics FLUENT code. The results show that the computation results of the independently developed code are consistent with those of the FLUENT code, and the deviation is within the acceptable range in engineering. However, the computation efficiency of the code is significantly higher than that of the FLUENT code. It's preliminarily indicated that SPATANS code can be used in the thermal-hydraulic analysis for spent fuel assembly of sodium cooled fast reactor, and there is a good prospect of application. (authors)