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针对剧烈传热情况下超临界水堆堆芯稳态性能分析程序SNTA与SRAC堆芯轴向功率分布计算结果偏差较大的问题,分析偏差产生的主要原因.逐一排查影响因素,确认轴向功率分布偏差主要源于截面反馈作用不同.SRAC程序与SNTA程序采用的截面数据库和能群结构不同,SRAC程序计算的反应性密度系数相对较大,密度分布与功率分布的反馈作用更为显著,轴向功率分布曲线更为陡峭.相较于SRAC程序,采用精细能群结构的SNTA程序更适用于具备强核热耦合特性且中子能谱偏硬的超临界水堆堆芯的耦合计算与性能分析.“,”A coupled neutronics/thermal-hydraulics (N/T) three dimensional code system SNTA is developed for SCWR core steady state analysis.This paper studies the calculation difference between the SNTA code and the SRAC code.By using the impacts exclusive method,it is confirmed that the calculation difference between these two code is caused by the different feedback of the reaction cross-section.The reaction cross-section data and the energy group structure of the SRAC code differs from the SNTA code,and the density coefficient of reactivity calculated by the SRAC code is higher,which means the feedback of the density and power distribution is bigger and the axial power distribution varies rapidly.Compare to the SRAC code,the SNTA is more suitable for the SCWR core steady state analysis by coupling neutronics and thermal-hydraulics.