AbstractThis paper shows that a 20% initial mixing inhomogeneity of deuterium (D) and tritium (T) fuels and also a 30% T reduction in a D-T pellet still give a sufficient fusion energy output in D-T inertial confinement fusion (ICF). One and two dimensional numerical simulations and estimation studies support these results. The results mean that fusion energy output and burn process are rather insensitive to the significant T reduction and to the initial inhomogeneous fuel mixing in the D-T ICF pellet.