JFET_V5_N1_A1 Magdi Ragheb Journal on Future Engineering and Technology 2230 – 7184 5 1 1 14 Hybrid Reactors, Fusion, Fission, Deuterium, Tritium, Lithium, Thorium Cycle, Molten Salt, Sodium, Plutonium, Uranium, Beryllium, Fluorine, Thermal Breeder, Breeding Blankets, Neutron Reactions The thorium fusion fission hybrid is discussed as a sustainable longer term larger resource base to the fast breeder fission reactor concept. In addition, it offers a manageable waste disposal process, burning of the produced actinides and serious nonproliferation characteristics. With the present day availability of fissile U-235 and Pu-239 , and available fusion and accelerator neutron sources, a new look at the thorium-U-233 fuel cycle is warranted. The use of the thorium cycle in a fusion fission hybrid could bypass the stage of fourth generation breeder reactors in that the energy multiplication in the fission part allows the satisfaction of energy breakeven and the Lawson condition in magnetic and inertial fusion reactor designs. This allows for the incremental development of the technology for the eventual introduction of a pure fusion technology.The nuclear performance of a fusion-fission hybrid reactor having a molten salt composed of Na-Th-F-Be as the blanket fertile material and operating with a catalyzed Deuterium-Deuterium (DD) plasma is compared to a system with a Li-Th-F-Be salt operating with a Deuterium-Tritium (DT) plasma. In a reactor with a 42-cm thick salt blanket followed by a 40-cm thick graphite reflector, the catalyzed DD system exhibits a fissile nuclide production rate of 0.88 Th(n,Y) reactions per fusion source neutron. The DT system, in addition to breeding tritium from lithium for the DT reaction yields 0.74 Th(n,Y) breeding reactions per fusion source neutron. Both approaches provide substantial energy amplification through the fusion-fission coupling process. Such an alternative sustainable paradigm or architecture would provide the possibility of a well optimized fusion-fission thorium hybrid using a molten salt coolant for sustainable long term fuel availability with the added advantages of higher temperatures thermal efficiency for process heat production, proliferation resistance and minimized waste disposal characteristics. August - October 2009 Copyright © 2009 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=1013