超临界水冷混合堆快谱区组件物理——热工分析

提出了超临界水冷混合堆快谱区多层燃料组件设计方案.应用MCNP程序为该组件建立计算模型,并进行了相应的物理计算;同时运用子通道分析程序STAFAS对多层燃料组件子通道进行了初步的稳态热工分析.计算结果表明:超临界水冷混合堆快谱区多层燃料组件燃料转换比超过1.0,并且获得负的冷却剂空泡反应性系数;燃料包壳表面最高温度约为595℃,低于设计准则规定的上限值,同时组件各子通道出口冷却剂温度均匀性较好.通过对燃料棒径敏感性分析可知,较大棒径组件燃料转换比较大,但也会导致热通道包壳表面温度峰值升高.

A neutron-kinetics/thermal-hydraulics analysis of the fast zone assembly in the SCWR mixed core

This paper proposes a multi-layer design of fuel assemblies for the fast zone of the SCWR mixed core. Both neutron-physical and thermal-hydraulic behavior of the multi-layer fuel assembly are analyzed using the MCNP code and the sub-channel analysis code STAFAS, respectively. The results show that with the proposed multi-layer structure the fast zone of the mixed core has breeding capability. At the same time, a negative void reactivity coefficient of coolant can be achieved. The peak temperature of fuel cladding is about 595 ℃, which is lower than the design limit. In addition, a well uniform distribution of the coolant temperature at the exit of the fuel assembly is obtained with the reference geometric parameters. A sensitivity analysis indicates that a larger fuel rod diameter leads to a higher conversion ratio,however, results in a higher peak temperature of fuel claddings.