用ATHLET程序分析NHR-5功率自跟随实验

Self power-following test analysis on the 5 MW nuclear heating reactor with the ATHLET code

ATHLET是德国核设施安全评审中心GRS开发的一个重要的反应堆热工水力学分析程序。为了全面评估ATHLET程序应用于清华大学核能与新能源技术研究院建造5MW低温核供热实验堆(NHR-5)的适用性,该文建立了5MW低温供热堆的ATHLET输入模型,以功率自跟随实验为模拟对象进行验证性计算分析。将结果与对应的实验结果、RETRAN-02程序的计算结果进行比较。曲线显示:反应堆上腔体压力、堆芯入口温度的ATHLET计算值和实验值之间的差异分别达到2×10-2M Pa和2.5K。分析结果表明,燃料元件表面过冷沸腾的空泡反应性反馈对取得良好的模拟计算结果有重要作用。

The computer code ATHLET （analysis of the thermal-hydraulics of leaks and transients） was developed by GRS （Gesellschaft for Anlagen-und Reaktorsicherheit） for transient analysis of the thermal-hydraulics of light water reactors. The applicability of the ATHLET code＇s transient analysis for the NHR-5 heating reactor at Institute of Nuclear and New Energy Technology of Tsinghua University was evaluated by simulating the self power-following test performed on the NHR-5. The test data are compared with the ATHLET predictions and with RETRAN-02 code calculations. The results show that the ATHLET predictions of the upper plenum pressure are 2 ×10^-2 MPa higher than the experimental data while the reactor core temperatures are 2.5 K higher. The analysis results indicate that the reactivity feedback in the highly sub-cooled boiling regime has a significant effect on the results.