In this study, a novel power generation cycle is presented which is a combination of the modified Kalina Cycle and the Gas Turbine-Module Helium Reactor system. The rejected heat from the GT-MHR cycle is supplied to drive the modified KC. Energy and exergy analysis is conducted applying Engineering Equation Solver (EES) software. Furthermore, concerning the mathematical modeling, the parametric study is implemented to assess the effect of the key parameters on the performance criteria of the GT-MHR with Kalina cycle. Additionally, the thermal efficiency of the system is optimized using Genetic algorithm. The result of the optimization demonstrates 53.2% for the thermal efficiency under the optimal values of 37.39% for ammonia concentration, 402 K for vapor generator temperature, 20.82 bar for vapor generator pressure, 9.582 bar for separator 2 pressure, and 2.603 for compressor pressure ratio. From the exergy analysis of the system, it is shown that the reactor core has the highest contribution to the exergy destruction rate. Although, the obtained exergy efficiency of the system is 53.2%. It is striking to regard that the combined KC and GT-MHR has higher energy and exergy efficiencies comparing to stand-alone KC and GT-MHR.