This work aimed to develop accelerator-driven systems (ADSs) with a subcritical thorium assembly for fuel breeding and clean energy utilization by using several seed fuels. The ADS reactor core was loaded with three different fuel types, namely, reprocessed fuel, UN, and UO2 (seed fuel) associated separately with ThO2 fuel (blanket) in a heterogeneous approach. The Monte Carlo code MCNPX 2.7.0 has been employed to calculate neutronic parameters such as the effective multiplication coefficient (Keff), the nuclear fuel evolution during the burnup for every case, and the power fraction from seed and blanket fuels. The results indicate that the utilization of thorium (without any contents of 233U at the beginning of cycle) with reprocessed fuel allowed more 233U production than the UN and UO2 cases but with shorter cycle length. Introducing thorium fuel with the UN into the ADS core presented an efficient method to produce thermal power with the longest cycle length approaching 20 years.