燃料棒包壳内表面温度的计算结果如图1所示。在寿期初，对于包壳内表面温度FORWARD的计算值约为400℃。 包壳内表面温度和芯块中心温度变化趋势基本一致，包括寿期中和寿期末温度的转折时间也是一样的。相比之下，包壳内表面温度的变化趋势更为平缓。

The calculated results of the inner surface temperature of the fuel rod cladding are shown in Figure 1. At the beginning of the service life, the calculated value of the inner surface temperature FORWARD of the cladding is about 400 ℃. The change trend of the inner surface temperature of the cladding is basically consistent with that of the core temperature of the pellet, including the transition time of the temperature during and at the end of the service life. In contrast, the change trend of the inner surface temperature of the cladding is more gentle.