We present a computational study of dt fusion driven by Coulomb explosion within a single, large, heteronuclear two-component D2/T2 nanodroplet, originating from kinematic overrun effects between deuterons and tritons. Scaled electron and ion dynamics simulations have been used to explore the size dependence and the isotopic composition dependence of the intra-nanodroplet (INTRA) dt fusion yield in a composite D2n-2kT 2k nanodroplet, initially consisting of an inner sphere of D 2 molecules surrounded by an outer sphere of T2 molecules (n = 1.4×108-2.0×109, k/n = 0.10-0.60, and initial radii R0 = 1100-2700 Å) driven by a single, ultraintense, near-infrared, Gaussian laser pulse (peak intensity 10 20 Wcm-2, pulse length 25 fs). INTRA dt fusion in D 2n-2kT2k nanodroplets with neutron yields of 30-90 (per nanodroplet, per laser pulse) were attained in the size domain R0 = 2000-2700 Å with the optimal composition in the range of k/n = 0.2-0.4. INTRA yields in D2n-2kT2k nanodroplets are similar (within 20-40%) to those in initially homogeneous (DT)n nanodroplets of the same size. These INTRA yields are sufficiently large to warrant experimental observation in a single nanodroplet. The INTRA dt fusion can be distinguished from the inter-nanodroplet dt fusion reaction, which occurs inside and outside the macroscopic plasma filament, by the nanodroplet size dependence of the yield and by the different energies of the neutrons produced in these two channels.