The synergy of light and heavy water reactors using both uranium and thorium has been examined for the primary purpose of managing transuranic radionuclide (TRU) production. Two variants of a two-reactor system, where the first reactor uses uranium oxide fuel and the second reactor uses thorium-based fuels with a transuranic component, are analyzed from the perspective of TRU management. One variant uses low-enriched uranium made from natural uranium and uranium recovered from reprocessing in the first reactor, while the other variant uses highly enriched uranium. Full recycle of all actinides was used to minimize the amount of transuranics requiring repository disposal, so that the only source of exiting transuranics is from losses associated with process inefficiencies. Both variants compare favorably with other fuel cycle options with regards to the quantity of transuranic elements requiring geological disposal on an energy-normalized basis.