Bum simulations have been carried out for the DT ignitor/DD fuel pellet model by using a hydrodynamic code including neutron transport. The results showed that neutron heating has large effects on the bum performance, for instance the fusion yield and the internal tritium breeding ratio. The DD burning could be sustained by neutron heating and thus sufficient tritium could be bred by using one of the branches of the DD reaction, D + D → p + T. Furthermore, several treatments for neutron transport were compared. It was found that the treatment of the anisotropy of neutron scattering has a larger influence on the bum performance than the treatment of the time dependence of neutron transport. Finally a compressed state of the pellet was proposed as a candidate for the advanced fuel ICF reactor TAKANAWA-I.