快堆中,由于燃料组件内棒束排列紧凑,包壳内、外表面的周向温度变化较大。在棒束内,燃料棒偏离对称位置的时候更为明显。这种周向温度变化会引起燃料棒热弯曲,热点温度进一步升高,因而不得不降低整个组件的热功率。为了估价热点安全裕度,本文编写了三角形棒束中,燃料棒在正常位置或偏位时, In the fast reactor, due to the compact arrangement of the rod bundles within the fuel assembly, the circumferential temperature of the inner and outer surfaces of the cladding greatly changes. In the bundle, the fuel rods deviate from the symmetrical position more obvious. This circumferential temperature change causes the fuel rods to warp and further increase the hot spot temperatures, thereby having to lower the thermal power of the entire assembly. In order to assess the hot spot safety margins, this paper prepared a triangular bundle, the fuel rods in the normal position or deviation,