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In recent years, the use of Gas Turbine-Modular Helium Reactor (GT-MHR) which operates in accordance with closed Brayton cycle with helium fluid as working fluid has attracted researchers’ attention because of its high efficiency, high reactor safety, being economical, and low maintenance costs. In the present study, a combined system, including GT-MHR cycle, Kalina cycle and Ammonia-water absorption cycle is investigated with respect to energy, exergy, and exergoeconomic. As the bottoming cycle, Kalina cycle and absorption cycle are used in order to avoid energy wasted by gas turbine cycle and to increase efficiency of energy conversion. The results of the simulated model show that, in the basic input mode, the overall work is 304462 kW, the overall exergy destruction is 289766kW and the overall exergy efficeincy of cogeneration cycle is 0.689kW. Also reactor, turbine and compressor in helium cycle are the component to which more attention should be paid with respect to exergoeconomic because the highest amount of cost rate is related to these components. At the end, parametric analysis is carried out in order to evaluate the effect of the changing pressure ratio of helium compressor, input temperature of helium compressor, input pressure and temperature of turbine and mass fraction of the base mode of the Kalina cycle on the output parameters.