液态金属快增殖堆都选用低密度氧化铀钚混合燃料,其密度为理论密度的90%左右,其余为均匀分布的气孔。燃料晶粒度为5—10μm,气孔尺寸大于1μm。运行时燃料处在高温及陡峭的温度梯度下,气孔在燃料的蒸发冷凝机制下,朝晶界及温度梯度的反方向迁移,结果在燃料中心形成中心孔,其外是边界十分清晰的环状结 Liquid metal fast breeder reactor are selected low-density uranium oxide plutonium mixed fuel, the density of about 90% of the theoretical density, and the remaining uniform distribution of pores. Fuel grain size of 5-10μm, pore size greater than 1μm. Under high temperature and steep temperature gradient, the flue gas migrates toward the grain boundary and the temperature gradient in the evaporation and condensation of the fuel during operation. As a result, the center hole is formed in the center of the fuel, and the boundary is very clear Knot