To further improve achievable Isp for NTR systems, a method is proposed to augment propellant heating with an arcjet or magnetohydrodynamic (MHD) system. In this rocket cycle, the propellant gains energy in the reactor as usual, however, instead of being exhausted through a nozzle, the propellant is (1) introduced directly into a large turbopump assembly, (2) directed back through the reactor core, and (3) finally directed into the arcjet or MHD thruster. This hybrid system approach can provide very high propellant temperatures and higher Isp. A detailed system analysis will be accomplished to determine the benefits and performance of a hybrid NTR/Arc Jet system. The outcomes will be (1) a system model adaptable for specific mission analysis and (2) detailed analysis for developing such a hybrid system.