2GW功率下CFETR中子屏蔽的初步中子学研究

在中国聚变工程实验堆(CFETR)真空室最新设计尺寸下，利用蒙特卡洛中子输运程序(MCNP)建立一维中子学模型，在2GW 的聚变功率下进行了计算。分析了中子反射材料ZrH₂ 对中子的屏蔽效果，发现200mm 的反射层可以屏蔽94.3%的中子通量和94.9%的中子核热。研究CFETR 在运行10 个满功率年(FPY)和20FPY 后，对应不同中子壁载荷的最小屏蔽包层厚度。结果显示，装置运行10FPY 后中子壁载荷在1.0MW·m⁻²、1.5MW·m⁻²、 2.5MW·m⁻² 时所对应的最小屏蔽包层厚度分别为44cm、53cm、65cm；而在装置运行20FPY 后，则需要在径向方向更厚的屏蔽包层才能满足中子屏蔽要求。屏蔽包层的尺寸优化将为目前阶段的CFETR 先进包层设计提供参考。

Preliminary neutronics analysis of neutron shielding for CFETR with 2GW fusion power

Using a one-dimensional (1D) neutronics model, the neutronics performance in the China fusion engineering test reactor (CFETR) with latest design dimensions of vacuum vessel is calculated under the 2GW fusion power. The shielding effect of neutron reflecting material ZrH₂ on neutrons is calculated, and it is found that the 20cm reflector can shield 94.3% neutron fluence and 94.9% neutron nuclear heat. Meanwhile, the minimum shield blanket thickness corresponding to different neutron wall loads is calculated when CFETR is operated at 10FPY (full power year) and 20FPY. The results show that the minimum shield blanket thickness are 44cm, 53cm, and 65cm corresponding to the neutron wall loads with 1.0MW·m⁻², 1.5MW·m⁻², and 2.5MW·m⁻² respectively after the device is operated at 10 FPY; whereas the shielding blanket needs to be thicker in the radial direction to meet the neutron shielding requirements after the device is operated at 20FPY. The optimized size of the shielding blanket provides a significant reference for the design of CFETR advanced blanket.