三代非能动核电厂乏燃料贮运系统衰变热计算及关键因素研究

The decay heat calculation and key factors study on spent fuel storage and transportation system of third generation nuclear power plant

本文以三代非能动核电厂国和一号乏燃料组件为研究对象,基于ANS5.1—2005和ORIGEN-S软件的衰变热计算开展对比研究,分析了不同冷却时间下裂变产物、锕系元素衰变热变化规律。结果显示,对于冷却时间在5年以上的乏燃料,锕系元素占总衰变热的贡献接近20%甚至更高,锕系元素的主要贡献来自于Cm-244、Pu-238和Am-241。ANS 5.1-2005对锕系元素仅考虑了U-239和Np-239,对于冷却时间较长的乏燃料贮运系统,相对ANS 5.1—2005,ORIGEN-S衰变热计算结果更加保守。建议在三代非能动核电厂乏燃料的贮运系统衰变热计算中采用基于ORIGEN-S等类似功能的专用程序进行计算。

In this paper,based on the spent fuel assembly from the third generation passive nuclear power plant,a comparative study on the decay heat calculation based on ANS 5.1—2005 and ORIGEN-S was carried out.The variation of decay heat of fission products and actinide nuclides under different cooling times is analyzed in detail.The results show that the contribution of actinide nuclides to the total decay heat of spent fuel with cooling time of more than 5 years is close to 20%or even higher,and the main contributions of actinide nuclides are from Cm-244,Pu-238 and Am-241.ANS 5.1—2005 only considers U-239 and Np-239 for actinide nuclides.For the spent fuel storage system with long cooling time,the calculation of decay heat by ANS 5.1—2005 is not conservative.It is suggested that special programs such as ORIGEN-S should be used to calculate the decay heat for the third generation passive NPP spent fuel storage and transportation system.